Process for forming deposited film

ABSTRACT

A process for forming a deposited film comprises introducing into a film forming space housing a substrate therein an active species (A) formed by decomposition of a compound containing silicon and a halogen and an active species (B) formed from a chemical substance for film formation which is chemically mutually reactive with said active species (A) separately from each other, then providing them with discharge energy and thereby allowing both the species to react chemically with each other to form a deposited film on the substrate.

This application is a continuation of application Ser. No. 07/391,675filed Aug. 8, 1989, now abandoned, which is a continuation ofapplication Ser. No. 06/831,412 filed Feb. 20, 1986, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a process suitable for forming a depositedfilm, above all a functional film, particularly an amorphous orcrystalline deposited film to be used for semiconductor devices,photosensitive devices for electrophotography, line sensors for imageinput, image pick-up devices, photovoltaic devices etc.

2. Description of the Prior Art

For example, for formation of an amorphous silicon film, an amorphousgermanium film, etc. the vacuum deposition method, the plasma CVDmethod, the CVD method, the reactive sputtering method, the ion platingmethod, the optical CVD method or the like have been attempted to bepracticed, and, in general, the plasma CVD method has widely been usedand industrialized.

However, for the deposited film constituted of amorphous silicon,amorphous germanium, etc. there is room loft for further improvement ofoverall characteristics with respect to electrical or opticalcharacteristics and fatigue characteristic in repeated uses, or useenviron$ mental characteristic, further productivity and massproductivity including uniformity and reproducibility.

The reaction process in formation of an amorphous silicon depositedfilm, an amorphous germanium deposited film, etc. according to theplasma CVD method generalized in the prior art is considerablycomplicated as compared with the CVD method of the prior art, and not afew ambiguities existed in its reaction mechanism. Also, there areinvolved a large number of parameters for formation of such a depositedfilm (e.g. substrate temperature, flow rates and ratios of gasesintroduced, pressure during file formation, high frequency power,electrode structure, structure of reaction vessel, gas dischargingspeed, plasma generation system, etc.), and the plasma formed bycombination of such a large number of parameters may sometimes becomeunstable to frequently give markedly bad influences to the depositedfilm formed. Besides, the parameters inherent in the device must bechosen for each device, and it has been difficult under the presentsituation to generalize the production conditions. On the other hand,for exhibiting electrical, optical, photoconductive or mechanicalcharacteristics of an amorphous silicon film, an amorphous germaniumfilm, etc. satisfactorily for respective uses, it has been deemed bestto form such a film according to the plasma CVD method under the presentsituation.

However, depending on the applied uses of the deposited film, since itis required to meet sufficiently requirements of enlargement of area,uniformization of film thickness and uniformity of film quality, andalso to attempt to perform a mass production with reproducibility by ahigh speed film formation, enormous equipment capital becomes necessaryfor mass production devices in formation of amorphous silicon depositedfilm, amorphous germanium deposited films, etc. according to the plasmaCVD method, and the management items for mass production thereof willbecome complicated to make the management tolerance narrower. Thesematters, and also subtlety in adjustment of the devices, have beenpointed out as the problems to be improved in the future. On the otherhand, in conventional CVD method of the prior art, high temperature isrequired to be used and no deposited film having practicalcharacteristics could be obtained.

As described above, in formation of amorphous silicon films, amorphousgermanium films, etc. it has earnestly been desired to develop aformation process which can perform mass production by means of a lowcost device while maintaining practical characteristics and uniformity.These discussions may also be applicable to other functional films suchas silicon nitride films, silicon carbide films, silicon oxide films,etc.

SUMMARY OF THE INVENTION

The present invention provides a novel process for formation of adeposited film which removes the drawbacks of the plasma CVD method asdescribed above and also uses no formation method of tho prior art.

An object of the present invention is to provide a process for forming adeposited film which is suitable for enlargement of the film and caneasily accomplish improvement of productivity and mass production of thefilm while attempting to improve the characteristics of the film formedthe film forming speed and reproducibility and also to uniformize filmquality.

According to the present invention, there is provided a process forforming a deposited film, which comprises introducing into a filmforming space housing a substrate therein an active species (A) formedby decomposition of a compound containing silicon and a halogen and anactive species (B) formed from a chemical substance for film formationwhich is chemically mutually reactive with said active species (A)separately from each other, then providing them with discharge energyand thereby allowing both the species to react chemically with eachother to form a deposited film on the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view for illustration of a constructionexample of the image forming member for electrophotography produced byuse of the process of the present invention;

FIG. 2 is a schematic sectional view for illustration of a constructionexample of a PIN type diode produced by use of the process of thepresent invention; and

FIG. 3 and FIG. 4 are schematic diagrams of illustration of theconstitutions of the devices for practicing the process of the presentinvention employed in respective examples.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the process of the present invention, discharge energy capable ofgenerating an activation atmosphere such as plasma, etc. is used as anenergy for exciting and causing materials for formation of depositedfilms to react with each other, and is applied to both active species(A) formed by decomposition of a compound containing silicon and ahalogen and active species (B) formed from a chemical substance for filmformation coexisting in a film forming space, thereby causing,accelerating or amplifying chemical mutual reaction. Therefore, itbecomes possible to form films by use of lower discharge energy than wasused in the prior art, and deposited films thus formed are free from badinfluence by etching action or other actions such as abnormaldischarging action, etc. during film formation.

Also, according to the present invention, by controlling the atmospheretemperature in the film forming space and the substrate temperature asdesired, the CVD process can be made more stable.

Further, if desired, light energy and/or heat energy can be used incombination with discharge energy. Since light energy can be applied byuse of an appropriate optical system, to the whole substrate orselectively and controllably to a desired portion of the substrate, theposition, thickness, etc. of the deposited film to be formed on thesubstrate can easily be controlled. Also, heat energy converted fromlight energy can be used.

One of the points in which the process of the present invention isdifferent from the CVD process of the prior art is to use active speciesobtained by being previously activated in a space different from thefilm forming space (hereinafter referred to as activation space). Bydoing so, the film forming speed can be dramatically increased ascompared with the CVD method of the prior art. In addition, thesubstrate temperature during film formation can be lowered to a greatextent, whereby deposited films with stable film quality can be providedcommercially in a large amount and yet at low cost.

The term active species (A) as herein mentioned refers to those havingthe action of promoting formation of deposited films by causing chemicalmutual actions with the active species (B) formed from a chemicalsubstance for film formation, thereby imparting energy or causingchemical reactions to occur. Thus, the active species (A) may eithercontain the constituent elements which become the constituent elementsconstituting the deposited film to be formed or contain no suchconstituent element.

In the present invention, as the compound containing silicon and halogento be introduced into the activation space (A), there may be employed,for example, chain or cyclic hydrogenated silicon of which hydrogenatoms are partially or wholly substituted with halogen atoms, typicallychain silicon halides represented by Si_(u) Z_(2u+2) (u is an integer of1 or more, Z is at least one element selected from F, Cl, Br and I),cyclic silicon halides represented by Si_(v) Z_(2v) (v is an integer of3 or more, and has the same meaning as defined above), and chain orcyclic compounds represented by Si_(u) H_(x) Z_(y) (u and Z have thesame meanings as defined above, x+y=2u or 2u+2).

Specific examples may include gaseous or readily gasifiable compoundssuch as SiF₄, (SiF₂)₆, (SiF₂)₅, (SiF₂)₄, Si₂ F₆, Si₃ F₈, SiHF₃, SiH₂ F₂,SiCl₄, (SiCl₂)₅, SiBr₄, (SiBr₂)₅, Si₂ Cl₆, Si₂ Br₆, SiHCl₃, SiHBr₃,SiHI₃, Si₂ Cl₃ F₃, and the like.

For formation of the active species (A), in addition to the abovecompound containing carbon and halogen, (and the compound containingsilicon and halogen), other silicon compounds such as single substanceof silicon, etc., hydrogen, a halogen compound (e.g. F₂ gas, Cl₂ gas,gasified Br₂, I₂, etc.) may be used in combination.

Chemical substances for film formation to be used in the presentinvention are supplied with activation energy in the activation space(B) to be activated, thereby forming the active species (B). The activespecies (B) is then introduced into the film forming space and reactmutually by the action of discharge energy with the foregoing activespecies (A) simultaneously introduced from the activation space (A),thus resulting in easy formation of a desired deposited film on adesired substrate.

As the chemical substance for film formation for forming the activespecies (B) used in the present invention, there may be included thosecontaining the constituent elements which become the constituentelements constituting the deposited film to be formed and functioning asa starting material for formation of the deposited film or those notcontaining the constituent elements which become the constituentelements constituting the deposited film to be formed and capable ofbeing considered to merely contribute to film formation. The compoundsfunctioning as a starting material for formation of the deposited filmand the compounds contributing to film formation may be used incombination.

The chemical substance for film formation t be used in the presentinvention may preferably be already gaseous or made gaseous beforeintroduction into activation space (B). For example, when a liquidcompound is used, a suitable gasifying device can be connected to thesource for supplying the compound, and the compound can be gasifiedbefore introduction into the activation space (B).

In the activation space (B) to be used in the process of the presentinvention, as the above chemical substance for film formation forforming active species (B), hydrogen gas and/or a halogen compound (e.g.F₂ gas, Cl₂ gas, gasified Br₂, I₂, etc.) may be advantageously employed.Also, in addition to these chemical substances for film formation, aninert gas such as helium, argon, neon, etc. may be used. When aplurality of these chemical substances for film formation are to beemployed, they can be previously mixed before introduction into theactivation space (B). or alternatively these chemical substances canindividually be supplied from feeding sources independent of each otherto be introduced into the activation space (B), or into independentrespective activation spaces to be individually activated therein.

In the activation space (B) to be used in the process of the presentinvention, as the above chemical substance for film formation forforming active species (B), there may also be advantageously employedsilicon containing compounds, carbon containing compounds, germaniumcontaining compounds, oxygen containing compounds and nitrogencontaining compounds.

As the silicon containing compound, there may be employed unsubstitutedor substituted silanes having hydrogen, halogen and hydrocarbon groupsbonded to silicon. Above all, chain or cyclic silane compounds and thosechain and cyclic silane compounds of which hydrogen atoms aresubstituted partially or wholly with halogen atoms are preferred.

Specifically, there may be included, for example, straight chain silanecompounds represented by Si_(p) H_(2p+2) (p is an integer of 1 or more,preferably 1 to 15, more preferably 1 to 10) such as SiH₄, Si₂ H₆, Si₃H₈, Si₄ H₁₀, Si₅ H₁₂, Si₆ H₁₄, etc. which may be substituted withhalogen; branched chain silane compounds represented by Si_(p) H_(2p+2)(p has the same meaning as mentioned above) such as SiH₃ SiH(SiH₃)SiH₃,SiH₃ SiH(SiH₃)Si₃ H₇, Si₂ H₅ SiH(SiH₃)Si₂ H₅, etc. which may besubstituted with halogen; and cyclic silane compounds represented bySi_(q) H_(2q) (q is an integer of 3 or more, preferably 3 to 6) such asSi₃ H₆, Si₄ H₈, Si₅ H₁₀, Si₆ H₁₂, etc. which may be substituted withother cyclic silanyl groups and/or chain silanyl groups. Examples of theabove silane compounds in which a part or all of the hydrogen atoms aresubstituted with halogen atoms may include halo-substituted chain orcyclic silane compounds represented by Si_(r) H_(s) X_(t) (X is ahalogen atom, r is an integer of 1 or more, preferably 1 to 10, morepreferably 3 to 7, s+t=2r+2 or 2r) such as SiH₃ F, SiH₃ Cl, SiH₃ Br,SiH₃ I. etc. These compounds may be used either alone or as acombination of two or more compounds.

In the above case, in addition to the silicon containing compounds forfilm formation, it is possible to introduce one or more kinds of theaforesaid hydrogen gas, a halogen compound (e.g. F₂ gas, Cl₂ gas,gasified Br₂, etc.) and an inert gas such as helium, argon, neon. etc.into the activation space (B). When a plurality of these chemicalsubstances for film formation are to be employed, they can be previouslymixed before introduction into the activation space (B), oralternatively these starting gases can individually be supplied fromfeeding sources independent of each other to be introduced into theactivation space (B), or into independent respective activation spacesto be individually activated therein.

As the carbon containing compound, there may be employed preferablygaseous or readily gasifiable compounds selected from chain or cyclicsaturated or unsaturated hydrocarbon compounds, organic compoundscontaining carbon and hydrogen as main constituent atoms andadditionally containing at least one of halogen, sulfur, etc. asconstituent atoms, and organic silicon compounds containing hydrocarbongroups as constituent components or having silicon-carbon bonds.

Among them, as hydrocarbon compounds, there may be enumerated saturatedhydrocarbons having 1 to 5 carbon atoms, ethylenic hydrocarbons having 2to 5 carbon atoms, acetylenic hydrocarbons having 2 to 4 carbon atoms,including specifically, as saturated hydrocarbons, methane (CH₄), ethane(C₂ H₆), propane (C₃ H₈), n-butane (n-C₄ H₁₀), pentane (C₅ H₁₂); asethylenic hydrocarbons, ethylene (C₂ H₄), propylene (C₃ H₆), butene-1(C₄ H₈), butene-2(C₄ H₈), isobutylene (C₄ H₈), pentene (C₅ H₁₀); asacetylenic hydrocarbons, acetylene (C₂ H₂), methylacetylene (C₃ H₄),butyne (C₄ H₆), etc.

As halo-substituted hydrocarbon compounds, there may be enumeratedcompounds in which at least one of hydrogen atoms which are constituentsof the above hydrocarbon compounds are substituted with F, Cl, Br or I,particularly those in which hydrogen is substituted with F or Cl, aseffective ones.

The halogens substituted for hydrogen may be either one kind or two ormore kinds in one compound.

As organic silicon compounds to be used in the present invention mayinclude organosilanes and organohalogenosilanes.

Organosilanes and organohalogenosilanes are compounds represented,respectively, by the general formulae:

    R.sub.n SiH.sub.4-n and R.sub.m SiX.sub.4-m

wherein R is alkyl or aryl; X is F, Cl, Br or I; n=1,2,3 or 4; and m=1,2or 3, including typically alkylsilanes, arylsilanes,alkylhalogenosilanes, and arylhalogenosilanes.

Specific example of organochlorosilanes include

    ______________________________________                                        trichloromethylsilane                                                                              CH.sub.3 SiCl.sub.3,                                     dichlorodimethylsilane                                                                             (CH.sub.3).sub.2 SiCl.sub.2,                             chlorotrimethylsilane                                                                              (CH.sub.3).sub.3 SiCl,                                   trichloroethylsilane C.sub.2 H.sub.5 SiCl.sub.3 and                           dichlorodiethylsilane                                                                              (C.sub.2 H.sub.5).sub.2 SiCl.sub.2.                      ______________________________________                                    

Specific examples of organochlorofluorosilanes include

    ______________________________________                                        chlorodifluoromethylsilane                                                                         CH.sub.3 SiF.sub.2 Cl,                                   dichlorofuloromethylsilane                                                                         CH.sub.3 SiFCl.sub.2,                                    chlorofulorodimethylsilane                                                                         (CH.sub.3).sub.2 SiFCl,                                  chloroethyldifluorosilane                                                                          (C.sub.5 H.sub.5)SiF.sub.2 Cl,                           dichloroethylfluorosilane                                                                          C.sub.2 H.sub.5 SiFCl.sub.2,                             chlorodifluoropropylsilane                                                                         C.sub.3 H.sub.7 SiF.sub.2 Cl and                         dichlorofluoropropylsilane                                                                         C.sub.3 H.sub.7 SiFCl.sub.2.                             ______________________________________                                    

Specific examples of organosilanes include

    ______________________________________                                        tetramethylsilane   (CH.sub.3).sub.4 Si,                                      ethyltrimethylsilane                                                                              (CH.sub.3).sub.3 SiC.sub.2 H.sub.5,                       trimethylpropylsilane                                                                             (CH.sub.3).sub.3 SiC.sub.3 H.sub.7,                       triethylmethylsilane                                                                              CH.sub.3 Si(C.sub.2 H.sub.5).sub.3 and                    tetraethylsilane    (C.sub.2 H.sub.5).sub.4 Si.                               ______________________________________                                    

Specific examples or organohydrogenosilanes include

    ______________________________________                                        methylsilane        CH.sub.3 SiH.sub.3,                                       dimethylsilane      (CH.sub.3).sub.2 SiH.sub.2,                               trimethylsilane     (CH.sub.3).sub.3 SiH,                                     diethylsilane       (C.sub.2 H.sub.5).sub.2 SiH.sub.2,                        triethylsilane      (C.sub.2 H.sub.5).sub.3 SiH,                              tripropylsilane     (C.sub.3 H.sub.7).sub.3 SiH and                           diphenylsilane      (C.sub.6 H.sub.5).sub.2 SiH.sub.2.                        ______________________________________                                    

Specific examples of organofluorosilanes include

    ______________________________________                                        trifluoromethylsilane                                                                              CH.sub.3 SiF.sub.3,                                      difluorodimethylsilane                                                                             (CH.sub.3).sub.2 SiF.sub.2,                              fluorotrimethylsilane                                                                              (CH.sub.3).sub.3 SiF,                                    ethyltrifluorosilane C.sub.2 H.sub.5 SiF.sub.3,                               diethyldifluorosilane                                                                              (C.sub.2 H.sub.5).sub.2 SiF.sub.2,                       triethylfulorosilane (C.sub.2 H.sub.5).sub.3 SiF and                          trifluoropropYlsilane                                                                              (C.sub.3 H.sub.7)SiF.sub.3.                              ______________________________________                                    

Specific examples of organobromosilanes include

    ______________________________________                                        bromotrimethylsilane (CH.sub.3).sub.3 SiBr and                                dibromodimethylsilane                                                                              (CH.sub.3).sub.2 SiBr.sub.2.                             ______________________________________                                    

In addition, it is also possible to use organopolysilanes, for example,

    ______________________________________                                        organodisilanes such as                                                       ______________________________________                                        hexamethyldisilane   [(CH.sub.3).sub.3 Si].sub.2 and                          hexapropyldisilane   [(C.sub.3 H.sub.7).sub.3 Si].sub.2.                      ______________________________________                                    

These carbon containing compounds may be used either alone or as acombination of two or more compounds.

In the above case, in addition to the carbon containing compounds, oneor more kinds of hydrogen halogen compounds (e.g. F₂ gas, Cl₂ gas,gasified Br₂, I₂, etc.) inert gases such as helium, neon, argon, etc.and the aforesaid silicon compounds may be introduced into theactivation space (B). When a plurality of these chemical substances forfilm formation are to be employed, they can be previously mixed in agaseous state before introduction into the activation space (B), oralternatively these starting gases for film formation can individuallybe supplied from feeding sources independent of each other to beintroduced into the activation space (B), or into independent respectiveactivation spaces to be individually activated therein.

As the germanium containing compounds, there may be employed inorganicor organic germanium containing compounds having hydrogen, halogens orhydrocarbon groups bonded to germanium, as exemplified by organicgermanium compounds such as chain or cyclic hydrogenated germaniumrepresented by Ge_(a) H_(b) (a is an integer of 1 or more, b=2a+2 or2a); polymers of the hydrogenated germanium; compounds in which a partor all of the hydrogen atoms in the above hydrogenated germanium aresubstituted with halogen atoms; compounds in which a part or all of thehydrogen atoms in the above hydrogenated germanium compounds aresubstituted with organic groups such as alkyl groups, aryl groups, etc.or, if desired, halogen atoms; etc. and inorganic germanium compoundssuch as sulfide, imides etc.

Specifically, there may be enumerated, for example, GeH₄, Ge₂ H₆, Ge₃H₈, n-Ge₄ H₁₀, tert-Ge₄ H₁₀, Ge₃ H₆, Ge₅ H₁₀, GeH₃ F, GeH₃ Cl, GeH₂ F₂,H₆ GeF₆, Ge(CH₃)₄, Ge(C₂ H₅)₄, CH₃ GeH₃, (CH₃)₂ GeH₂, (CH₃)₃ GeH, (C₂H₅)₂ GeH₂, Ge(CH₃)₂ F₂, GeF₂, GeF₄, GeS, Ge₃ N₄, Ge (NH₂)₂, etc.

These germanium compounds may be used either alone or as a combinationof two or more compounds.

In the above case, in addition to the germanium containing compounds,one or more kinds of hydrogen, a halogen compound (e.g. F₂ gas, Cl₂ gas,gasified Br₂, I₂, etc.). an inert gas such as helium, neon, argon, etc.compounds aforesaid silicon containing compoumds or carbon containingmay be introduced into the activation space (B). When a plurality ofthese chemical substances for film formation are to be employed, theycan be previously mixed in a gaseous state before introduction into theactivation space (B), or alternatively these starting gases for filmformation can individually be supplied from feeding sources independentof each other to be introduced into the activation space (B), or intoindependent respective activation spaces to be individually activatedtherein.

As the oxygen containing compound, there may be mentioned compoundscontaining oxygen atoms and at least one atom other than oxygen asconstituent atoms. Other atoms than oxygen as mentioned above includehydrogen (H), halogens (X=F, Cl, Br or I). sulfur (S), carbon (C),silicon (Si), germanium (Ge), phosphorus (P), boron (B), alkali metals,alkaline earth metals, transition metals, etc. In addition, still otheratoms, of elements belonging to the respective groups in the periodictable, which can be bonded to an oxygen atom may be available.

For example, as compounds containing O and H, there may be enumerated H₂O, H₂ O₂, etc.; as compounds containing O and S, oxides such as SO₂,SO₃, etc.; as compounds containing O and C, oxides such as CO, CO₂,etc.; as compounds containing O and Si, siloxanes such as disiloxane (H₃SiOSiH₃), trisiloxane (H₃ SiOSiH₂ OSiH₃), etc., organoacetoxylilanessuch as diacetoxydimethylsilane (CH₃)₂ Si(OCOCH₃)₂,triacetoxymethylsilane CH₃ Si(OCOCH₃)₃, etc., alkylalkoxysilanes such asmethoxytrimethylsilane (CH₃)₃ SiOCH₃, dimethoxydimethylsilane (CH₃)₂Si(OCH₃)₂, trimethoxymethylsilane CH₃ Si(OCH₃)₃), etc.; organosilanolssuch as trimethylsilanol (CH₃)₃ SiOH, dimethylphenyl silanol (CH₃)₂ (C₆H₅)SiOH, diethylsilanediol (C₂ H₅)₂ Si(OH)₂, etc.; as compoundscontaining O and Ge, oxides, hydroxides of Ge, germanic acids, organicgermanium compounds such as H₃ GeOGeH₃, H₃ GeOGeH₂ OGeH₃, etc.. but theoxygen containing compounds to be used in the present invention are notlimited to these compounds.

These oxygen containing compounds may be used either alone or as acombination of two or more compounds.

Also, it is possible to use gases other than these compounds such as O₂,O₃, etc.

In the above case, in addition to the oxygen containing compounds, it ispossible to introduce at least one of hydrogen, halogen compounds (e.g.F₂ gas, Cl₂ gas, gasified Br₂, I₂, etc.), inert gases such as helium,neon, argon, etc. and the aforesaid silicon containing compounds, carboncontaining compounds or germanium containing compounds into theactivation space (B). When a plurality of these chemical substances forfilm formation are to be employed, they can be previously mixed in agaseous state before introduction into the activation space (B), oralternatively these chemical substances for film formation canindividually be supplied from feeding sources independent of each otherto be introduced into the activation space (B), or into independentrespective activation spaces to be individually activated therein.

As the nitrogen containing compound, there may be included compoundscontaining nitrogen atoms and at least one atom other than nitrogen asconstituent atoms. Other atoms than nitrogen as mentioned above includehydrogen (H), halogens (X=F, Cl, Br or I), sulfur (S), carbon (C),oxygen (O), phosphorus (P), silicon (Si), germanium (Ge), boron (B),alkali metals, alkaline earth metals, transition metals, etc. Inaddition, still other atoms, of elements belonging to the respectivegroups in the periodic table, which can be bonded to an nitrogen atommay be available.

For example, as compounds containing N and H, there may be enumeratedNH₃, NH₄ H₃, N₂ H₅ N₃, H₂ NNH₂, primary to tertiary amines, halides ofthese amines, hydroxylamine, etc.; as compounds containing N and X, N₃X, N₂ X₂, NX₃, NOX, NO₂ X, NO₃ X₄, etc.; as compounds containing N andS, N₄ S₄, N₂ S₅, etc.; as compounds containing N and C, N(CH₃)₃, HCN andcyanides, HOCN and salts thereof, etc.; as compounds containing N and O,N₂ O, NO, NO₂, N₂ O₃, N₂ O₄, N₂ O₅, NO₃, etc; as compounds containing Nand P, P₃ N₅, P₂ N₃, PN, etc. In addition, there may also be employedorganosilazanes such as triethylsilazane (C₂ H₅)₃ SiNH₂,hexamethyldisilazane [(CH₃)₃ Si]₂ NH, hexaethyldisilazane [(C₂ H₅)₃ Si]₂NH, etc.; organosilicon isocyanates such as trimethylsilicon isocyanate(CH₃)₃ SiNCO, dimethylsilicon diisocyanate (CH₃)₂ Si(NCO)₂, etc.;organosilicon isothiocyanates such as trimethylsilicon isothiocyanate(CH₃)₃ SiNCS, etc. The nitrogen containing compound is not limited tothese compounds provided that the compound is fit for attaining theobject of the present invention.

These nitrogen containing compounds may be used either alone or as acombination of two or more compounds. Also, it is possible to use N₂gas.

In the above case, in addition to the nitrogen containing compounds, itis possible to introduce at least one of hydrogen, halogen compounds(e.g. F₂ gas, Cl₂ gas, gasified Br₂, I₂, etc.), inert gases such ashelium, neon, argon, etc. and the aforesaid silicon containingcompounds, carbon containing compounds, germanium containing compoundsor oxygen containing compounds into the activation space (B). When aplurality of these chemical substances for film formation are to beemployed, they can be previously mixed in a gaseous state beforeintroduction into the activation space (B), or alternatively thesechemical substances for film formation can individually be supplied fromfeeding sources independent of each other to be introduced into theactivation space (B), or into independent respective activation spacesto be individually activated therein.

In the present invention the proportion in amount of the active species(A) to the active species (8) in the film forming space may suitably bedetermined depending on the depositing conditions, the kind of activatedspecies, etc., but may preferably be 10:1 to 1:10, more preferably 8:2to 4:6.

In the present invention, as the method for forming activate species (A)and (B) in the activation spaces (A) and (B), respectively, there may beemployed various activation energies such as electrical energiesincluding microwave, RF, low frequency, DC, etc., heat energiesincluding heater heating, IR-ray heating, etc., optical energies and thelike in view of the respective conditions and the device.

On the other hand, the deposited film formed according to the presentinvention can be doped with impurity elements during or after filmformation. As the impurity elements to be used, there may be employed,as p-type impurities, elements belonging to group III A of the periodictable such as B, Al, Ga, In, Tl, etc. and, as n-type imputities,elements belonging to group VA of the periodic table such as N, P, As,Sb, Bi, etc. as suitable ones. Particularly, B, Ga, P and Sb are mostpreferred. The doping amount of impurities may be determined suitablydepending on the desired electrical and optical characteristics.

Among compounds containing such impurity atoms as the components, it ispreferable to select a compound which is gaseous under normaltemperature and normal pressure, or gaseous t least under the activatingconditions, or a compound which can be readily gasified by a suitablegasifying device. Such compounds include PH₃, P₂ H₄, PF₃, PF₅, PCl₃,AsH₃, AsF₃, AsF₅, AsCl₃, SbH₃, SbF₅, BiH₃, BF₃, BCl₃, BBr₃, B₂ H₆, B₄H₁₀, B₅ H₉, B₅ H₁₁, B₆ H₁₀, B₆ H₁₂, AlCl₃, etc.. The compoundscontaining impurity atoms may be used either alone or as a combinationof two or more compounds

The substances for introduction of impurities may be introduced into theactivation space (A) and/or the activation space (B) together with therespective substances for formation of the active species (A) and theactive species (B) to be activated therein alternatively activated in athird activation space (C) separate from the activation space (A) andthe activation space (B). The substance for introduction of impurity canbe employed by selecting suitably the activation energy as describedabove. The active species formed by activation of the substance forintroduction of impurity (PN) may be previously mixed with the activespecies (A) and/or the active species (B) before introduction into thefilm forming space or independently introduced into the film formingspace.

Next, the present invention is described by referring to a typicalexample of the image forming member for electrophotography formed by theprocess of the present invention.

FIG. 1 is a schematic sectional view for illustration of theconstruction example of a typical photoconductive member obtained by thepresent invention.

Photoconductive member 10 shown in FIG. 1 is applicable as an imageforming member for electrophotography, and has a layer constitutionconsisting of intermediate layer 12 which may optionally be provided andphotosensitive layer 13 provided on substrate 11 for photoconductivemember.

In preparation of the photoconductive member 10, intermediate layer 12and /or the photosensitive member 13 can be prepared according to theprocess of the present invention. Further, when the photoconductivemember 10 has an protective layer provided for the purpose of protectingchemically or physically the surface of the photosensitive layer 13, ora lower barrier layer and/or an upper barrier layer provided forimproving dielectric strength, these layers can also be preparedaccording to the process of the present invention.

The substrate 11 may be either electroconductive or insulating. Aselectroconductive substrates, there may be mentioned metals such asNiCr, stainless steel, Al, Cr, Mo, Au, Ir, Nb, Ta, V, Ti, Pt, Pd, etc.or alloys thereof.

As insulating substrates, there may conventionally be used films orsheets of synthetic resins, including polyesters, polyethylene,polycarbonates, cellulose acetate, polypropylene, polyvinyl chloride,polyvinylidene chloride, polystyrene, polyamides, etc., glasses,ceramics, papers and so on. At least one side surface of thesesubstrates is preferably subjected to treatment for impartingelectroconductivity, and it is desirable to form other layers on theside at which said electroconductive treatment has been applied.

For example, electroconductive treatment of a glass can be effected byproviding a thin film of NiCr, Al, Cr, Mo, Au, Ir, Nb, Ta, V, Ti, Pt,Pd, In₂ O₃, SnO₂, ITO(In₂ O₃ +SnO₂), etc. thereon. Alternatively, asynthetic resin film such as a polyester film can be subjected to theelectroconductive treatment on its surface by, for example, vacuum vapordeposition, electron-beam deposition or sputtering of a metal such asNiCr, Al, Ag, Pb, Zn, Ni, Au, Cr, Mo, Ir, Nb, Ta, v, Ti, Pt, etc. or bylaminating treatment with the said metal, thereby impartingelectroconductivity to the surface. The substrate may be shaped in anyform such as cylinders, belts, plates or others, and its form may bedetermined as desired. For example, when the photoconductive member 10in FIG. 1 is to be used as a light-receiving member forelectrophotography, it may desirably be formed into an endless belt or acylinder for use in continuous high speed copying.

For example, the intermediate layer 12 has the function of impedingeffectively inflow of the carriers from the side of the substrate 11into the photosensitve layer 13 and permitting easy passage of thephotocarriers, formed in the photosensitive layer 13 by irradiation ofelectromagnetic wave and migrating toward the side of the substrate 11,from the side of the photosensitive layer 13 to the side of thesubstrate 11.

The intermediate layer 12 may be constituted of, for example, amorphoussilicon having a matrix of silicon atoms and optionally containinghydrogen atoms (H) and/or halogen atoms (X)(hereinafter written as"A-Si(H,X)"); amorphous silicon having a matrix of silicon atoms andoptionally containing hydrogen atoms (H) and/or halogen atoms (X) and/orcarbon atoms (hereinafter written as A-Si(H,X,C)); amorphous germaniumhaving a matrix of germanium atoms and optionally containing siliconatoms and/or hydrogen atoms (H) and/or halogen atoms (X) (hereinafterwritten as A-Ge(Si, H, X)"); amorphous material having a matrix ofsilicon atoms and germanium atoms and optionally containing hydrogenatoms (H) and/or halogen atoms (X) (hereinafter written as "A-SiGe(H,X)"); amorphous silicon having a matrix of silicon atoms and optionallycontaining hydrogen atoms (H) and/or halogen atoms (X) and/or oxygenatoms (O) (hereinafter written as "A-Si (H, X, O)"); amorphous siliconhaving a matrix of silicon atoms and nitrogen atoms and optionallycontaining hydrogen atoms (H) and/or halogen atoms (X) (hereinafterwritten as "A-SiN(H,X)"), etc. and at the same time can sometimescontain, for example, a p-type impurity such boron as boron (B) or ann-type impurity such as phosphorus (P) as a substance for controllingelectroconductivity, if necessary.

In the present invention, the content of substances controllingconductivity such as B, P, etc. contained in the intermediate layer 12may preferably be 0.001 to 5×10⁴ atomic ppm, more preferably 0.5 to1×10⁴ atomic ppm, optimally 1 to 5×10³ atomic ppm.

In the case of forming the intermediate layer 12, as starting materialsfor formation of the intermediate layer, active species (A) formed inactivation space (A) and active species (B) formed in activation space(B), optionally together with active species formed by activation ofhydrogen, halogens, inert gases, gases of silicon containing compounds,germanium containing compounds, carbon containing compounds, compoundscontaining impurity elements as components, etc. may be introducedrespectively and separately into the film forming space, in which thesubstrate 11 is placed, and the intermediate layer 12 may be formed onthe substrate 11 by applying discharge energy to the coexistenceatmosphere of the respective species introduced to cause chemicalreaction.

The compound containing silicon and halogen capable of forming activespecies (A) by introduction into the activation space (A) duringformation of the intermediate layer 12 should desirably be one selectedfrom the compounds as mentioned above which can form readily activespecies such as for example SiF₂ ^(*).

The intermediate layer 12 should have a layer thickness preferably 30 Åto 10μ, more preferably 40 Å to 8μ, optimally 50 Å to 5μ.

The photosensitive layer 13 is constituted of, for example, an amorphousmaterial having a matrix of silicon atoms and optionally containinghydrogen atoms and/or halogen atoms (X) as constituent atoms(hereinafter referred to as "A-Si(H,X)"); an amorphous siliconA-Si(H,X,Ge) having a matrix of silicon atoms and optionally containinghydrogen, halogen, germanium, etc. as constituent atoms; amorphoussilicon germanium A-SiGe(H,X) having a matrix of silicon atoms andgermanium atoms and optionally containing hydrogen, halogen, etc. asconstituent atoms, and the like, and has both functions of the chargegeneration function of generating photocarriers by irradiation of laserbeam and the function of transporting the charges.

The photosensitive layer 13 should have a layer thickness preferably of1 to 100μ, more preferably 1 to 80μ, optimally 2 to 50μ.

The photosensitive layer 13 is constituted of non-doped A-Si(H,X), butit may also contain a substance for controlling conductivitycharacteristic with a polarily different from the polarity of thesubstance for controlling conductivity characteristic contained in theintermediate layer 12 (e.g. n-type), if desired, or a substance of thesame polarity may be contained therein, when the practical amountcontained in the intermediate layer 12 is much, in an amount by farsmaller than said amount.

Formation of the photosensitive layer 13 may be practiced, similarly asin the case of the intermediate layer 12, if it is to be preparedaccording to the process of the present invention, by introducing acompound containing silicon and halogen into the activation space (A),decomposing these under a high temperature or exciting these through theaction of discharge energy or light energy to form active species (A)and introducing the active species (A) into the film forming space.

In the case of forming a intermediate layer 12 which is similar to orthe same in constituents as the photosensitive layer 13, up to formationof the photoconductive layer 13 can continuously be performed subsequentto formation of the intermediate layer 12.

Further, if desired, it is also possible to form an amorphous depositedfilm containing carbon and silicon as constituent atoms as the surfacelayer on the photosensitive layer and, in this case, film formation canalso be conducted according to the process of the present invention,similarly as the above intermediate layer and photosensitive layer.

FIG. 2 is a schematic illustration showing a typical example of a PINtype diode device utilizing a deposited film doped with an impurityelement prepared by carrying out the process of the present invention.

In the drawing, 21 is a substrate, 22 and 27 are thin film electrodes,23 is a semiconductor film consisting of an n-type semiconductor layer24, an i-type semiconductor layer 25 and a p-type A-Si semiconductorlayer 26. While the present invention may be applicable for preparationof all of the semiconductor layers 24, 25 and 26, particularly thesemiconductor layer 26 can be prepared according to the process of thepresent invention to enhance conversion efficiency. When thesemiconductor layer 26 is prepared by the process of the presentinvention, the semiconductor layer 26 can be constructed of for example,an amorphous material having a matrix of silicon atoms and optionallycontaining hydrogen atoms and/or halogen atoms (X) as constituent atoms(hereinafter referred to as "A-Si(H,X); an amorphous materialA-SiGe(H,X) having a matrix of silicon and germanium atoms andoptionally containing hydrogen atoms and/or halogen atoms (X) asconstituent atoms; an amorphous material A-Si(H,X,Ge) having a matrix ofsilicon atoms and optionally hydrogen atoms and/or halogen atoms and/orgermanium atoms, as constituent atoms; an amorphous material A-Ge(H,X)having a matrix of germanium atoms and optionally containing hydrogenatoms and/or halogen atoms (X) as constituent atoms; an amorphousmaterial A-Si(O,H,X) having a matrix of silicon atoms and optionallycontaining oxygen atoms and/or hydrogen atoms and/or halogen atoms asconstituent atoms; an amorphous material A-Si(N,H,X) having a matrix ofsilicon atoms and optionally containing nitrogen atoms and/or hydrogenand/or halogen atoms as constituent atoms, etc. 28 is a conductive wireto be connected to the external electrical circuit.

As the substrate 21, there may be employed a conductive, semiconductiveor insulating substrate.

When the substrate 21 is conductive, the thin film electrode 22 may beomitted. As the semiconductive substrate, there may be employed, forexample, semiconductors such as Si, Ge, GaAs, ZnO, ZnS, etc. Thin filmelectrodes 22, 27 can be obtained by forming thin films of NiCr, Al, Cr,Mo, Au, Ir, Nb, Ta, V, Ti, Pt, Pd, In₂ O₃, SnO₂, ITO(In₂ O₃ +SnO₂), etc.on the substrate 21 by treatment such as vacuum deposition, electronbeam vapor deposition, sputtering, etc. The electrodes 22, 27 have afilm thickness preferably of 30 to 5×10⁴ Å, more preferably 100 to 5×10³Å.

For rendering the film constituting the semiconductor layer n-type orp-type, if desired, it can be formed by doping an n-type impurity or ap-type impurity or both impurities into the layer to be formed, whilecontrolling its amount, during layer formation.

For formation of n-type, i-type and p-type semiconductor layers, any oneor all of the layers can be formed by the process of the presentinvention, with the film formation being performed by introducing acompound containing silicon and halogen, into the activation space (A),then exciting and decomposing these by the action of an activationenergy, whereby active species (A) of, for example, SiF₂ ^(*), etc. canbe formed and introduced into the film forming space. Also, separately,chemical substances for film formation introduced into the activationspace (B), optionally together with an inert gas and a gas containing animpurity element as the component, may be respectively excited anddecomposed by respective activation energies to form respective activespecies, which are then separately or in an appropriate mixtureintroduced into the film forming space in which substrate 11 is placedto form a deposited film by use of discharge energy. The n-type andp-type semiconductor layers should have a layer thickness preferably of100 to 10⁴ Å, more preferably 300 to 2000 Å. On the other hand, thei-type semiconductor layer should preferably have a layer thicknesspreferably of 500 to 10⁴ Å, more preferably 1000 to 10000 Å.

The PIN type diode device shown in FIG. 2 is not necessarily required toprepare all the layers of P, I and N according to the process of thepresent invention, and the present invention can be carried out bypreparing at least one layer of P, I and N according to the process ofthe present invention.

The process of the present invention is preferably applicable to, otherthan the above embodiment, forming SiO₂ insulator films or partiallyoxidized Si films which constitute semiconductor devices such as IC's,transistors, diodes, photoelectric conversion elements and the like.Also, Si films having an oxygen concentration distribution in the layerthickness direction can be obtained by controlling, for example, thetime, the amount, etc. of introducing the oxygen containing compoundinto the film forming space. Otherwise, in addition to the oxygencontaining compound, the silicon containing compounds, the germaniumcontaining compounds, the carbon containing compounds, etc. mayoptionally be used in combination to form a film having bonds of O withSi, Ge, C, etc. as constituting units and having desiredcharacteristics.

Futhermore, the process of the present invention is preferablyapplicable to forming Si₃ N₄ insulator films or partially nitrogenatedSi films which are formed by the CVD method and constitutessemiconductor devices such as IC's, transistors, diodes, photoelectricconversion elements and the like. Also, Si films having a nitrogenconcentration distribution in the layer thickness direction can beobtained by controlling, for example, the time, the amount, etc. ofintroducing the nitrogen containing compound into the film formingspace. Otherwise, in addition to the nitrogen containing compound,hydrogen, halogens, the silicon containing compounds, the germaniumcontaining compounds, the carbon containing compounds, the oxygencontaining compounds, etc. may optionally be used in combination to forma film having bonds of N with H, X, Si, Ge, C, O, etc. as constitutingunits and having desired characteristics.

According to the process for forming a deposited film of the presentinvention electrical, optical photoconductive and mechanicalcharacteristics desired for the film to be formed can be improved, andyet a high speed film formation is possible. Also, reproducibility infilm formation can be improved to enable improvement of the film qualityand uniformization of the film quality, and the process is alsoadvantageous in enlargement of area of the film and can easilyaccomplish improvement of productivity of films as well as bulkproduction of films. Further, since relatively low discharge energy canbe used as an excitation energy during film formation, there can beexhibited such effects that film formation can be effected also on asubstrate which is poor in heat resistance and that the steps can beshortened by low temperature treatment.

The present invention is described by referring to the followingExamples.

Example 1

By means of the device as shown in FIG. 3, i-type, p-type and n-typeA-Si(H,X) deposited film was formed according to the operation asdescribed below.

In FIG. 3, 101 is a film forming chamber, and a desired substrate 103 isplaced on a substrate supporting stand 1O₂ provided internally therein.

104 is a heater for heating the substrate, and electricity is suppliedthrough a conductive wire 105 to generate heat. The substratetemperature is not particularly limited, but it should preferably be 30°to 450° C., more preferably 50° to 300° C., when it is required to heatthe substrate in practicing the process of the present invention.

106 through 109 are gas feeding systems, and they are providedcorresponding to the kinds of the gases for film formation, and inertgases optionally employed, and the gases of the compounds containingimpurity element as the component. When these gases employed are liquidunder the standard condition, a suitable gasifying device is provided.

In the drawing, symbols of the gas feeding sources 106 through 109affixed with a are branched pipes, those affixed with b flowmeters,those affixed with c pressure gauges for measuring the pressures on thehigher pressure side of the respective flowmeters, those affixed with dor e valves for controlling the flow rates of respective gases. 123 isthe activation chamber (B) for forming active species (B) and, aroundthe activation chamber 123, there is provided the microwave plasmagenerating device 122 for generating activation energy for formation ofactive species (B). The starting gas for formation of active species (B)supplied from the gas inflow pipe 110 is activated in the activationchamber (B), and the active species (B) formed is introduced through theinflow pipe 124 into the film forming chamber 101. 111 is a gas pressuregauge.

In the drawing, 112 shows an activation chamber (A), 113 an electricfurnace, 114 solid Si particles and 115 a pipe for introduction of agaseous compound containing silicon and halogen as the starting materialfor active species (A). The active species (A) formed in the activationchamber (A) 112 is introduced through the inflow pipe 116 into the filmforming chamber 101.

117 is a discharging energy generating device and is provided with amatching box 117a, a cathode electrode for introduction of highfrequency 117b, etc.

The discharging energy from the discharging energy generating device 117is permitted to act on the active species flowing in the direction ofthe arrowhead 119, and the respective active species subjected to theaction undergo mutually chemical reaction thereby to form a depositionfilm of A-Si(H,X) on the whole or the desired portion of the substrate103. In the drawing, 120 shows a gas discharging valve and 121 a gasdischarging pipe.

First, a polyethyleneterephthalate film 103 was placed on a supportingstand 102, and the film forming chamber 101 was evacuated by use of anevacuating device (not shown) to about 10⁻⁶ Torr. From a gas feedingsource 106, H₂ gas at 150 SCCM or a gas mixture thereof with PH₃ gas orB gas (each being diluted to 1000 ppm with hydrogen gas) at 40 SCCM wasintroduced into the activation chamber (B) 123 through the gas inflowpipe 110. H₂ gas, etc. introduced into the activation chamber (B) 123was activated by means of the microwave plasma generating device 122 tobe converted to activated hydrogen, etc., which were then introducedthrough the inflow pipe 124 into the film forming chamber 101.

On the other hand, the activation chamber (A) 112 was packed with solidSi particles 114, heated by the electric furnace 113 to be maintained atabout 1100° C., thereby bringing Si into red hot state, whereinto SiF₄was blown through the inflow pipe 115 from the bomb not shown, thusforming active species of SiF₂ ^(*), which were then introduced into thefilm forming chamber 101 via the inflow pipe 116.

While maintaining the inner pressure in the film forming chamber 101 at0.4 Torr, plasma was allowed to act from the discharging device 117 toform a non-doped or doped A-Si(H,X) film (film thickness 700 Å). Thefilm forming speed was 51 Å/sec.

Subsequently, the non-doped or p-type A-Si(H,X) film sample was placedin a vacuum deposition tank, wherein a comb-type Al-gap electrode(length 250 Å, width 5 mm) was formed under vacuum of 10⁻⁵ Torr, and thedark electroconductivity σ_(d) was determined by measuring dark currentat an applied voltage of 10 V for evaluation of the film characteristicsof the respective samples. The results are shown in Table 1A.

Example 2

Except for introducing F₂ gas in addition to H₂ gas from the gas feedingbomb 106 (gas ratio H₂ /F₂ =15), A-Si(H,X) film was formed following thesame procedure as in Example 1. The dark electroconductivities weremeasured for respective samples to obtain the results shown in Table 1A.

From Table 1A, it can be seen that A-Si(H,X) films excellent inelectrical characteristics can be obtained according to the presentinvention and also that A-Si(H,X) films sufficiently doped can beobtained.

Example 3

By means of the device as shown in FIG. 4, a drum-shaped image formingmember for electrophotography with a layer constitution as shown in FIG.1 was prepared according to the operations as described below.

In FIG. 4, 201 shows a film forming chamber, 202 an activation chamber(A), 203 an electric furnace, 204 solid Si particles, 205 an inflow pipefor the starting material of active species (A), 206 a pipe forintroducing active species. 207 a motor, 208 a heater which is usedsimilarly as 104 in FIG. 3, 209 and 210 are blowing pipes, 211 acylindrical substrate such as aluminum cylinder, etc. and 212 a gasdischarging valve. 213 through 216 are starting gas feeding sourcessimilarly as 106 through 109 in FIG. 3, and 217-1 is a gas introducingpipe.

In the film forming chamber 201, the aluminum cylinder 211 is suspended,equipped internally thereof with the heater 208 so as to be rotatablewith the motor 207. 218 is a discharging energy generating device, andis provided with a matching box 218a and a cathode electrode 218b forintroduction of high frequency.

Also, the activation chamber (A) 202 was packed with solid Si particles204, heated by the electric furnace 203 to be maintained at about 1100°C. to bring Si into red hot state, whereinto SiF₄ was blown from bombnot shown to form active species of SiF₂ ^(*), which were thenintroduced into the film forming chamber 201 via the inflow pipe 206.

On the other hand, through the inflow pipe 217-1, H₂ gas was introducedinto the activation chamber (B) 220. The H₂ gas introduced was subjectedto activation treatment such as plasma formation by means of themicrowave plasma generating device 220 in the activation chamber (B) 220to become activated hydrogen, which was then introduced through theinflow pipe 217-2 into the film forming chamber 201. During thisoperation, if desired, impurity gases such as PH₃, B₂ H₆, etc. were alsoactivated by introduction into the activation chamber (B) 220. Whilemaintaining the pressure in the film forming chamber 201 at 1.0 Torr,plasma generated from the discharging device 218 was allowed to act.

The aluminum cylinder 211 was heated by the heater 208 to 220° C.,maintained thereat and rotated, while the discharging gas was dischargedby controlling adequately the opening of the discharging valve 212.Thus, photosensitive layer 13 was formed.

Also, the intermediate layer 12 was formed to a film thickness of 2000 Åby introducing a gas mixture of (0.2% of B₂ H₆ in terms of vol. %)through the inflow pipe 217-1.

Comparative example 1

According to the plasma CVD method in general, an image forming memberfor electrophotography having a layer constitution as shown in FIG. 1was formed by use of respective gases of SiF₄, H₂ and B₂ H₆ by means ofthe device having the same film forming chamber as the film formingchamber 201 provided with a high frequency means of 13.56 MHz.

The conditions for preparation of the drum-shaped image forming membersfor electrophotography obtained in Example 3 and Comparative example 1and their performances are shown in Table 2A.

Example 4

By means of the device as shown in FIG. 3, a PIN type diode as shown inFIG. 2 was prepared.

First, a polyethylenenaphthalate film 21 having ITO film 22 with athickness of 1000 Å vapor deposited thereon was placed on a supportingstand and, after reduced to a pressure of 10⁻⁶ Torr, active species SiF₂^(*) formed similarly as in Example 1 was introduced into the filmforming chamber 101. H₂ gas, PH₃ gas (diluted to 1000 ppm with hydrogengas) were respectively introduced into the activation chamber (B) 123through inflow pipe 110 to be activated. Subsequently, the activatedgases were introduced through the inflow pipe 124 into the film formingchamber 101. While maintaining the pressure in the film forming chamber101 at 0.1 Torr, plasma was permitted to act from the discharging device117 to form a n-type A-Si(H,X) film 24 (film thickness: 700 Å) dopedwith P.

Next, according to the same method as in formation of the n-typea-Si(H,X) film except for stopping introduction of PH₃ gas, a non-dopedtype A-Si(H,X) film 25 (film thickness: 5000 Å) was formed.

Subsequently, by use of diborane gas (B₂ H₆ gas diluted to 1000 ppm withhydrogen gas) together with H₂ gas, following otherwise the sameconditions as in the case of n-type, a p-type A-Si(H,X) film 26 (filmthickness: 700 Å) doped with B was formed. On this p-type film wasfurther formed by vapor deposition an aluminum electrode 27 with athickness of 1000 Å to provide a PIN type diode.

The diode element thus obtained (area 1 cm²) was subjected tomeasurement of I-V characteristic, and rectifying characteristic andphotovoltaic effect were evaluated. The results are shown in Table 3A.

Also, in photoirradiation characteristics, light was introduced from thesubstrate side, and a conversion efficiency of 8.3% or higher, an openend voltage of 1.08 V and a short circuit current of 10.1 mA/cm² wereobtained at a photoirradiation intensity AMI (about 100 mW/cm²).

Example 5

Except for introducing in addition to the H₂ gas from the inflow pipe110 (H₂ /F₂ =10), the same PIN type diode as in Example 4 was prepared.The rectifying characteristic and photovoltaic effect were evaluated inthis sample and the results are shown in Table 3A.

From Table 3A, it can be seen that an A-Si(H,X) PIN type diode havinggood optical and electrical characteristics can be obtained according tothe present invention.

Example 6

By means of the device as shown in FIG. 3, i-type, p-type and n-typeA-Si(H,X) deposited films were formed according to the operations asdescribed below.

In FIG. 3, 101 is a film forming chamber, and a desired substrate 103 isplaced on a substrate supporting stand 102 provided internally therein.

104 is a heater for heating the substrate, which heater 104 is used forheating treatment of the substrate 103 before the film forming treatmentor, after film formation, for annealing treatment for furtherimprovement of the characteristics of the film formed, and electricityis supplied through a conductive wire 105 to generate heat. Thesubstrate temperature is not particularly limited, but it shouldpreferably be 30° to 450° C., more preferably 50° to 300° C., when thesubstrate is required to be heated in practicing the process of thepresent invention.

106 through 109 are gas feeding systems, and they are providedcorresponding to the number of the starting materials for film formationand hydrogen, halogen compounds, inert gases, gases of the compoundscontaining impurities as the component, which may optionally be employedWhen these gases employed are liquid under the standard condition, asuitable gasifying device is provided. In the drawing, symbols of thegas feeding sources 106 through 109 affixed with a are branched pipes,those affixed with b flowmeters, those affixed with c pressure gaugesfor measuring the pressures on the higher pressure side of therespective flowmeters, those affixed with d or e valves for controllingthe flow rates of respective gases. 123 is the activation chamber (B)for forming active species (B) and, around the activation chamber 123,there is provided the microwave plasma generating device 122 forgenerating activation energy for formation of active species (B). Thestarting gas for formation of active species (B) supplied from the gasinflow pipe 110 is activated in the activation chamber (B), and theactive species (B) formed is introduced through the inflow pipe 124 intothe film forming chamber 101. 111 is a gas pressure gauge. In thedrawing, 112 shows an activation chamber (A), 113 an electric furnace,114 solid Si particles and 115 a pipe for introduction of a gaseouscompound containing silicon and halogen as the starting material foractive species (A). The active species (A) formed in the activationchamber 112 (A) is introduced through the inflow pipe 116 into the filmforming chamber 101.

117 is a discharging energy generating device 20 and is provided with amatching box 117a and a cathode electrode 117b for introduction of highfrequency, etc.

The discharging energy from the discharging energy generating device 117is permitted to act on the active species flowing in the direction ofthe arrowhead 119, and the active species subjected to the actionundergo mutually chemical reaction thereby to form a deposited film ofA-Si(H,X). In the drawing, 120 shows a gas discharging valve and 121 agas discharging pipe. First, a polyethyleneterephthalate film 103 wasplaced on a supporting stand 102, and the film forming chamber 101 wasevacuated by use of an evacuating device (not shown) to about 10⁻⁶ Torr.From a gas feeding source 106, Si₅ H₁₀ at 150 SCCM or a gas mixturethereof with PH₃ gas or B₂ H₆ gas (each being diluted to 1000 ppm withhydrogen gas) at 40 SCCM was introduced into the film forming chamber101. Si₅ H₁₀ gas, etc. introduced into the activation chamber (B) 123was activated by means of the microwave plasma generating device 122 tobe converted to hydrogenated silicon active species, etc., which werethen introduced through the inflow pipe 124 into the film formingchamber 101.

On the other hand, the activation chamber (A) 112 was packed with solidSi particles 114, heated by the electric furnace 113 to be maintained atabout 1100° C., thereby bringing Si into red hot state, whereinto SiF₄was blown through the inflow pipe 115 from the bomb not shown, thusforming active species of SiF₂ ^(*), which were then introduced into thefilm forming chamber 101 via the inflow pipe 116.

While maintaining the inner pressure in the film forming chamber 101 at0.4 Torr, plasma was allowed to act from the discharging device 117 toform a non-doped or doped A-Si(H,X) film (film thickness 700Å). The filmforming speed was 48 Å/sec.

Subsequently, the non-doped or p-type A-Si(H,X) film sample was placedin a vacuum deposition tank, wherein a comb-type Al-gap electrode(length 250μ, width 5 mm) was formed under vacuum of 10⁻⁵ Torr, and thedark electroconductivity σ_(d) was determined by measuring dark currentat an application voltage of 10 V for evaluation of the filmcharacteristics of the respective samples. The results are shown inTable 1B.

Examples 7-9

Except for using straight Si₄ H₁₀ , branched Si₄ H₁₀ or H₆ SiH₆ in placeof Si₅ H₁₀, the A-Si films were formed, following the same procedures asin Example 6. The dark electroconductivities were measured to obtain theresults shown in Table 1B.

From Table 1B, it can be seen that A-Si(H,X) films excellent inelectrical characteristics can be obtained according to the presentinvention and also that A-Si(H,X) films sufficiently doped can beobtained.

Example 10

By means of the device as shown in FIG. 4, a drum-shaped image formingmember for electrophotography with a layer constitution as shown in FIG.1 was prepared according to the operations as described below.

In FIG. 4, 201 shows a film forming chamber, 202 an activation chamber(A), 203 an electric furnace, 204 solid Si particles, 205 an inflow pipefor the starting material of active species (A), 206 a pipe forintroducing active species, 207 a motor, 208 a heater which is usedsimilarly as 104 in FIG. 3, 209 and 210 are blowing pipes, 211 analuminum cylinder substrate and 212 a gas discharging valve. 213 through216 are starting gas feeding sources similarly as 106 through 109 inFIG. 3, and 217-1 is a gas introducing pipe.

In the film forming chamber 201, the aluminum cylinder 211 is suspended,equipped internally thereof with the heater 208 so as to be rotatablewith the motor 207. 218 is a discharging energy generating device, andis provided with a matching box 218a, a cathode electrode 218b forintroduction of high frequency, etc.

Also, the activation chamber (A) 202 is packed with solid Si particles204, heated by the electric furnace 203 to be maintained at about 1100°C. to bring Si into red hot state, whereinto SiF₄ is blown to formactive species of SiF₂ ^(*), which are then introduced into the filmforming chamber 201 via the inflow pipe 206.

On the other hand, through the inflow pipe 217-1, respective Si₂ H₆ andH₂ gases are introduced into the activation chamber (B) 219. The Si₂ H₆and H₂ gases introduced are subjected to activation treatment such asplasma formation by means of the microwave plasma generating device 220in the activation chamber (B) 219 to become hydrogenated silicon activespecies, which are then introduced through the inflow pipe 217-2 intothe film forming chamber 201. During this operation, if desired,impurity gases such as PH₃, B₂ H₆, etc. are also activated byintroduction into the activation chamber (B) 219.

Then, while maintaining the pressure in the film forming chamber 201 at1.0 Torr, plasma generated from the discharging device 218 is allowed toact.

The aluminum cylinder 211 is heated by the heater 208° to 220° C.,maintained thereat and rotated, thile the discharging gas is dischargedby controlling adequately the opening of the discharging valve 212.Thus, a photosensitive layer 13 is formed.

Also, the intermediate layer 12 is formed prior to formation of thephotosensitive layer to a film thickness of 2000 Å by introducing Si₂ H₆and a gas mixture of H₂ /B₂ H₆ (0.2% of B₂ H₆ in terms of vol. %)through the inflow pipe 217-1.

Comparative example 2

According to the plasma CVD method in general, an image forming memberfor electrophotography having a layer constitution as shown in FIG. 1was formed by use of respective gases of SiF₄, Si₂ H₆, H₂ and B₂ H₆ bymeans of the device having the same film forming chamber as the filmforming chamber 201 provided with a high frequency means of 13.56 MHz.

The conditions for preparation of the drum-shaped image forming membersfor electrophotography obtained in Example 10 and Comparative example 2and their performances are shown in Table 2B.

Example 11

By means of the device as shown in FIG. 3, with the use of Si₃ H₆ as thesilicon compound, a PIN type diode as shown in FIG. 2 was prepared.

First, a polyethylenenaphthalate film 21 having ITO film 22 with athickness of 1000 Å vapor deposited thereon was placed on a supportingstand and, after reduced to a pressure of 10⁻⁶ Torr, active species SiF₂^(*) formed similarly as in Example 6 was introduced into the filmforming chamber 101.

Also, from the inflow pipe 110, Si₃ H₆ at 150 SCCM and PH₃ gases(diluted to 1000 ppm with hydrogen gas) were respectively introducedinto the activation chamber (B) to be activated. Next, the activatedgases were introduced through the inflow pipe 116 into the film formingchamber 101. While maintaining the pressure in the film forming chamberat 0.1 Torr and maintaining the substrate temperature at 250° C., plasmawas allowed to act from the discharging device 117 to form a n-typeA-Si(H,X) film 24 (film thickness 700 Å) doped with P.

Subsequently, by stopping introduction of PH₃ gas, following otherwisethe same conditions as in the case of n-type A-Si(H,X) film, non-dopedA-Si(H,X) film 25 (film thickness: 5000 Å) was formed.

Next, by use of B₂ H₆ gas (diluted to 1000 ppm with hydrogen gas) at 40SCCM together with H₂ gas, following otherwise the same conditions as inthe case of n-type A-Si(H,X) film 24, a p-type A-Si(H,X) film 26 (filmthickness: 700 Å) doped with B was formed. On this p-type film wasfurther formed by vapor deposition an aluminum electrode 27 with athickness of 1000 Å to provide a PIN type diode.

The diode element thus obtained (area 1 cm²) was subjected tomeasurement of I-V characteristic, and rectifying characteristic andphotovoltaic effect were evaluated. The results are shown in Table 3B.

Also, in photoirradiation characteristics, light was introduced from thesubstrate side, and a conversion efficiency of 7.9% or higher, an opencircuit voltage of 0.93 V and a short circuit current of 10.5 mA/cm²were obtained at a photoirradiation intensity AMI (about 100 mW/cm²).

Examples 12-14

Except for using straight chain Si₄ H₁₀, branched Si₄ H₁₀ or H₆ Si₆ F₆in place of Si₃ H₆, the PIN type diode was prepared in the same manneran in Example 11. The rectifying characteristic and photoelectromotiveeffect were evaluated and the results are shown in Table 3B.

From Table 3B, it can be seen that an A-Si(H,X) PIN type diode havingbetter optical and electrical characteristics as compared with the priorart can be obtained according to the present invention.

Example 15

By means of the device as shown in FIG. 3, i-type, p-type and n-typecarbon-containing amorphous carbon deposited films were formed accordingto the operations as described below.

In FIG. 3, 101 is a film forming chamber, and a desired substrate 103 isplaced on a substrate supporting stand 102 provided internally therein.

104 is a heater for heating the substrate, which heater 104 is used forheating treatment of the substrate 103 before the film forming treatmentor, after film formation, for annealing treatment for furtherimprovement of the characteristics of the film formed, and electricityis supplied through a conductive wire 105 to generate heat. Said heater104 is not driven during film formation. The heated substratetemperature is not particularly limited, but it should preferably be 30°to 450° C., more preferably 50° to 300° C., in practicing the process ofthe present invention.

106 through 109 are gas feeding systems, and they are providedcorresponding to carbon containing compounds, and the kinds of gasesoptionally employed such as hydrogen, halogen compounds, inert gases andcompounds containing impurity elements as the component. When thesegases employed are liquid under the standard condition, a suitablegasifying device is provided. In the drawing, symbols of the gas feedingsources 106 through 109 affixed with a are branched pipes, those affixedwith b flowmeters, those affixed with c pressure gauges for measuringthe pressures on the higher pressure side of the respective flowmeters,those affixed with d or e valves for controlling the flow rates ofrespective gases. 123 is the activation chamber (B) for forming activespecies (B) and, around the activation chamber 123, there is providedthe microwave plasma generating device 122 for generating activationenergy for formation of active species (B). The starting gas forformation of active species (B) supplied from the gas inflow pipe 110 isactivated in the activation chamber (B), and the active species (B)formed is introduced through the inflow pipe 124 into the film formingchamber 101. 111 is a gas pressure gauge. In the drawing, 112 shows anactivation chamber (A), 113 an electric furnace, 124 solid Si particlesand 115 a pipe for introduction a of a gaseous compound containingsilicon and halogen as the starting material for active species (A). Theactive species (A) formed in the activation chamber 112 is introducedthrough the inflow pipe 116 into the film forming chamber 101.

117 is a discharging energy generating device and, is provided with amatching box 117a, a cathode electrode 117b for introduction of highfrequency, etc.

The discharging energy from the discharging energy generating device 117is imparted to the active species flowing in the direction of thearrowhead 119, and the irradiated active species undergo mutuallychemical reaction thereby to form a deposited film of a-SiC(H,X) on thewhole or the desired portion of the substrate 103. In the drawing, 120shows a gas discharging valve and 121 a gas discharging pipe.

First, a polyethyleneterephthalate film 103 was placed on a supportingstand 102, and the film forming chamber 101 was evacuated by use of anevacuating device to about 10⁻⁶ Torr. From a gas feeding source 106, CH₄gas at 150 SCCM or a mixture thereof with PH₃ gas or B₂ H₆ gas (eachdiluted to 1000 ppm with hydrogen gas) at 40 SCCM was introduced intothe activation chamber (B) 123 through the gas inflow pipe 110.

CH₄ gas, etc. introduced into the activation chamber (B) 123 wasactivated by means of the microwave plasma generating device 122 to beconverted to hydrogenated carbon active species, activated hydrogen,etc., which were then introduced through the inflow pipe 124 into thefilm forming chamber 101.

On the other hand, the activation chamber (A) 112 was packed with solidSi particles 114, heated by the electric furnace 113 to be maintained atabout 1100° C., thereby bringing Si into red hot state, whereinto SiF₄was blown through the inflow pipe 115 from the bomb not shown, thusforming active species of SiF₂ ^(*), which were then introduced into thefilm forming chamber 101 via the inflow pipe 116.

While maintaining the inner pressure in the film forming chamber 101 at0.4 Torr, plasma was allowed to act from the discharging device to forma non-doped or a doped carbon-containing amorphous deposited film (filmthickness 700 Å). The film forming speed was 42 Å/sec.

Subsequently, the non-doped, p-type or n-type carbon containingamorphous film sample thus obtained was placed in a vacuum depositiontank, wherein a comb-type Al-gap electrode (gap length 250μ, width 5 mm)was formed under vacuum of 10⁻⁵ Torr, and the dark electroconductivityσ_(d) was determined by measuring dark current at an applied voltage of10 v for evaluation of the film characteristics of the respectivesamples. The results are shown in Table 1C.

Examples 16-18

Except for using straight chain C₂ H₆, C₂ H₄ or C₂ H₂ in place of CH₄,carbon-containing amorphous deposited films were formed. The darkelectroconductivities were measured to obtain the results shown in Table1C.

From Table 1C, it can be seen that amorphous carbon films excellent inelectrical characteristics can be obtained according to the presentinvention.

Example 19

By means of the device as shown in FIG. 4, a drum-shaped image formingmember for electrophotography with a layer constitution as shown in FIG.1 was prepared according to the operations as described below.

In FIG. 4, 201 shows a film forming chamber, 202 an activation chamber(A), 203 an electric furnace, 204 solid C particles, 205 an inflow pipefor the starting material of active species (A), 206 a pipe forintroducing active species, 207 a motor, 208 a heater which is usedsimilarly as 104 in FIG. 3, 209 and 210 are blowing pipes, 211 analuminum cylinder substrate and 212 a gas discharging valve. 213 through216 are starting gas feeding sources similarly as 106 through 109 inFIG. 1, and 217-1 is a gas introducing pipe.

In the film forming chamber 201, the aluminum cylinder 211 is suspended,equipped internally thereof with the heater 208 so as to be rotatablewith the motor 207. 218 is a discharging energy generating device, andis provided with a matching box 218a, a cathode electrode 218b forintroduction of high frequency.

Also, the activation chamber (A) 202 is packed with solid Si particles204, heated by the electric furnace 203 to be maintained at about 1100°C. to bring Si into hot state, whereinto SiF₄ is blown to form activespecies of SiF₂ ^(*), which are then introduced into the film formingchamber 201 via the inflow pipe 206.

On the other hand, through the inflow pipe 217-1, CH₄, Si₂ H₆ and H₂gases are introduced into the activation chamber (B) 219. The CH₄ gas,etc. introduced are subjected to activation treatment such as plasmaformation by means of the microwave plasma generating device 220 in theactivation chamber (B) 219 to become activated hydrogenated carbon,etc., which are then introduced through the inflow pipe 217-2 into thefilm forming chamber 201. During this operation, if desired, impuritygases such as PH₃, B₂ H₆, etc. are also activated by introduction intothe activation chamber (B) 219.

Then, while maintaining the pressure in the film forming chamber 201 at0.4 Torr, plasma is allowed to act from the discharging device.

The aluminum cylinder 211 is heated by the heater 208, maintained androtated, while the discharging gas is discharged through the dischargingvalve 212. Thus, a photosensitive layer 13 is formed.

Also, the intermediate layer 12 is formed prior to formation of thephotosensitive layer 13 to a film thickness of 2000 ° A by introducing agas mixture of H₂ /B₂ H₆ (0.2% of B₂ H₆ in terms of vol. %) through theinflow pipe 217-1.

Comparative example 3

According to the plasma CVD method in general, an image forming memberfor electrophotography having a layer constitution as shown in FIG. 1Cwas formed by use of respective gases of SiF₄, CH₄, Si₂ H₆, H₂ and B₂ H₆by means of the device having the same film forming chamber as the filmforming chamber 201 provided with a high frequency means of 13.56 MHz.

The conditions for preparation of the drum-shaped image forming membersfor electrophotography obtained in Example 19 and Comparative example 3and their performances are shown in Table 2C.

Example 20

By means of the device as shown in FIG. 3, with the use of CH₄ as thecarbon compound, a PIN type diode as shown in FIG. 2 was prepared.

First, a polyethylenenaphthalate film 21 having ITO film 22 with athickness of 1000 Å vapor deposited thereon was placed on a supportingstand and, after reduced to a pressure of 10⁻⁶ Torr, active species SiF₂^(*) were introduced into the film forming chamber 101 similarly as inExample 15. Also, from the inflow pipe 110, Si₃ H₆ at 150 SCCM and PH₃gas (diluted to 1000 ppm with hydrogen gas) were respectively introducedinto the activation chamber (B) 123 to be activated. Then, the activatedgases were introduced through the inflow pipe 116 into the film formingchamber 101. While maintaining the pressure in the film forming chamberat 0.4 Torr, plasma was allowed to act from the discharging device toform a n-type A-Si(H,X) film 24 (film thickness 700 Å) doped with P wasformed.

Next, according to the same method as in formation of the n-type A-Sifilm except for introducing B₂ H₆ gas (diluted to 300 ppm with hydrogengas) in place of PH₃ gas, an i-type a-Si film 25 (film thickness: 5000Å) was formed.

Subsequently, by using CH₄ at 50 SCCM and B₂ H₆ gas (diluted to 1000 ppmwith hydrogen gas) at 40 SCCM together with Si₃ H₆ gas in place of PH₃gas, following otherwise the same conditions as in the case of n-type, ap-type A-Si(H,X) film 26 (film thickness: 700 Å) doped with B wasformed. Further, on this p-type film was formed by vapor deposition analuminum electrode 27 with a thickness of 1000 Å to provide a PIN typediode.

The diode element thus obtained (area 1 cm²) was subjected tomeasurement of I-V characteristic, and rectifying characteristic andphotovoltaic effect were evaluated. The results are shown in Table 3C.

Also, in photoirradiation characteristics, light was introduced from thesubstrate side, and a conversion efficiency of 8.6% or higher, an opencircuit voltage of 0.90 V and a short circuit current of 10.6 mA/cm²were obtained at a photoirradiation intensity AMI (about 100 mW/cm²).

Examples 21-23

Except for using C₂ H₆, C₂ H₄ or C₂ H₂ in place of CH₄ as the carboncompound, a PIN type diode was prepared in the same manner as in Example20. The rectifying characteristic and photovoltaic effect were evaluatedand the results are shown in Table 3C.

From Table 3C, it can be seen that A-SiC(H,X) PIN type diode havingbetter optical and electrical characteristics as compared with the priorart can be obtained according to the present invention.

Example 24

By means of the device as shown in FIG. 3, i-type, p-type and n-typeA-SiGe(H,X) deposited films were formed according to the operations asdescribed below.

In FIG. 3, 101 is a film forming chamber, and a desired substrate 103 isplaced on a substrate supporting stand 102 provided internally therein.

104 is a heater for heating the substrate, which heater 104 is used forheating treatment of the substrate 103 before the film forming treatmentor, after film formation, for annealing treatment for furtherimprovement of the characteristics of the film formed, and electricityis supplied through a conductive wire 105 to generate heat.

The substrate temperature is not particularly limited, but it shouldpreferably be 30° to 450° C., more preferably 50° to 300° C., when thesubstrate is required to be heated in practicing the process of thepresent invention.

106 through 109 are gas feeding systems, and they are providedcorresponding to germanium-containing compounds, and the kinds of gasesoptionally employed such as hydrogen, halogen compounds, inert gases,silicon-containing compounds, carbon-containing compounds and compoundscontaining impurity elements as the component. When these gases employedare liquid under the standard condition, a suitable gasifying device isprovided.

In the drawing, symbols of the gas feeding sources 106 through 109affixed with a are branched pipes, those affixed with b flowmeters,those affixed with c pressure gauges for measuring the pressures on thehigher pressure side of the respective flowmeters, those affixed with dor e valves for controlling the flow rates of respective gases.

123 is the activation chamber (B) for forming active species (B) and,around the activation chamber 123, there is provided the microwaveplasma generating device 122 for generating activation energy forformation of active species (B). The starting gas for formation ofactive species (B) supplied from the gas inflow pipe 110 is activated inthe activation chamber (B), and the active species (B) formed isintroduced through the inflow pipe 124 into the film forming chamber101. 111 is a gas pressure gauge.

In the drawing, 112 shows an activation chamber (A), 113 an electricfurnace, 114 solid C particles and 115 a pipe for introduction of agaseous compound containing carbon and halogen as the starting materialfor active species (A). The active species (A) formed in the activationchamber 112 is introduced through the inflow pipe 116 into the filmforming chamber 101.

117 is a discharging energy generating device and is provided with amatching box 117a, a cathode electrode 117b for introduction of highfrequency, etc.

The discharging energy from the discharging energy generating device 117acts on the active species flowing in the direction of the arrowhead119, and the active species subjected to the action undergo mutuallychemical reaction thereby to form a deposited film of a-SiGe(H,X) on thewhole or the desired portion of the substrate 103. In the drawing, 120shows a gas discharging valve and 121 a gas discharging pipe.

First, a polyethyleneterephthalate film 103 was placed on a supportingstand 102, and the film forming chamber 101 was evacuated by use of anevacuation device to about 10⁻⁶ Torr. At the substrate temperatureindicated in Table 1D, from a gas feeding source 106, GeH₄ gas at 150SCCM, or a gas mixture thereof with PH₃ gas or B₂ H₆ gas (each dilutedto 1000 ppm with hydrogen gas) was introduced into the activationchamber (B) 123 through the gas inflow pipe 110. GeH₄ gas, etc.introduced into the activation chamber (B) 123 was activated by means ofthe microwave plasma generating device 122 to be converted to GeHm (m=1to 3) active species, activated hydrogen, etc., which were thenintroduced through the inflow pipe 124 into the film forming chamber101.

On the other hand, the activation chamber (A) 112 was packed with solidSi particles 114, heated by the electric furnace 113 to be maintained atabout 1100° C., thereby bringing Si into red hot state, whereinto SiF₄was blown through the inflow pipe 115 from the bomb not shown, thusforming active species of SiF₂ ^(*), which were then introduced into thefilm forming chamber 101 via the inflow pipe 116.

While maintaining the inner pressure in the film forming chamber 101 at0.4 Torr, plasma was allowed to act from the discharging device 117 toform non-doped or doped A-SiGe(H,X) films (film thickness 700 Å),respectively. The film forming speed was 38 Å/sec.

Subsequently, the non-doped or p-type A-SiGe(H,X) film sample obtainedwas placed in a vacuum deposition tank, wherein a comb-type Al-gapelectrode (gap length 250μ, width 5 mm) was formed under vacuum of 10⁻⁵Torr, and the dark electroconductivity σ_(d) was determined by measuringdark current at an applied voltage of 10 v for evaluation of the filmcharacteristics of the respective samples. The results are shown inTable 1D.

Examples 25-27

Except for using straight chain Ge₄ H₁₀, branched Ge₄ H₁₀, or H₆ Ge₆ F₆in place of GeH₄, A-SiGe(H,X) films were formed in the same manner as inExample 24. The dark electroconductivities were measured to obtain theresults shown in Table 1D.

From Table 1D, it can be seen that A-SiGe(H,X) films excellent inelectrical characteristics can be obtained and, also A-Ge(C,H,X) filmssubjected to satisfactory doping can be obtained according to thepresent invention.

Example 28

By means of the device as shown in FIG. 4, a drum-shaped image formingmember for electrophotography with a layer constitution as shown in FIG.1 was prepared according to the operations as described below.

In FIG. 4, 201 shows a film forming chamber, 202 an activation chamber(A), 203 an electric furnace, 204 solid Si particles, 205 an inflow pipefor the starting material of active species (A), 206 a pipe forintroducing active species, 207 a motor, 208 a heater which is usedsimilarly as 104 in FIG. 3, 209 and 210 are blowing pipes, 211 analuminum cylinder substrate and 212 a gas discharging valve. 213 through216 are starting gas feeding sources similarly as 106 through 109 inFIG. 1, and 217-1 is a gas introducing pipe.

In the film forming chamber 201, the aluminum cylinder 211 is suspended,equipped internally thereof with the heater 208 so as to be rotatablewith the motor 207. 218 is a discharging generating device, and isprovided with a matching box 218a, a cathode electrode 218b forintroduction of high frequency, etc.

Also, the activation chamber (A) 202 is packed with solid Si particles204, heated by the electric furnace 203 to be maintained at about 1100°C. to bring Si into red hot state, whereinto SiF₄ is blown to formactive species of SiF₂ ^(*), which are then introduced into the filmforming chamber 201 via the inflow pipe 206.

On the other hand, through the inflow pipe 217-1, Si₂ H₆, GeH₄ and H₂gases are introduced into the activation chamber (B) 219.

The Si₂ H₆, GeH₄ and H₂ gas introduced are subjected to activationtreatment such as plasma formation by means of the microwave plasmagenerating device 220 in the activation chamber (B) 219 to becomehydrogenated silicon active species, hydrogenated germanium species andactivated hydrogen, which are then introduced through the inflow pipe217-2 into the film forming chamber 201. During this operation, ifdesired, impurity gases such as PH₃, B₂ H₆, etc. are also activated byintroduction into the activation chamber (B) 220. Then, whilemaintaining the pressure in the film forming chamber 201 at 1.0 Torr,plasma generated from the discharging device 218 is allowed to act.

The aluminum cylinder 211 is maintained and rotated, while thedischarging gas is discharged by controlling adequately the opening ofthe discharging valve 212. Thus, a photosensitive layer 13 is formed.

Also, the intermediate layer 12 is formed prior to formation of thephotosensitive layer 13 to a film thickness of 2000 Å by introducing agas mixture of Si₂ H₆, GeH₄, H₂ and B₂ H₆ (0.2% of B₂ H₆ in terms ofvol. %) through the inflow pipe 217-1.

Comparative example 4

According to the plasma CVD method of prior art, a drum-shaped imageforming member for electrophotography having a layer constitution asshown in FIG. 1 was formed by use of respective gases of SiF₄ Si₂ H₆,GeH₄, H₂ and B₂ H₆ by means of the device having the same film formingchamber as the film forming chamber 201 provided with a high frequencymeans of 13.56 MHz.

The conditions for preparation of the drum-shaped image forming membersfor electrophotography obtained in Example 28 and Comparative example 4and their performances are shown in Table 2D.

Example 29

By means of the device as shown in FIG. 3, with the use of GeH₄ as thegermanium-containing compound, a PIN type diode as shown in FIG. 2 wasprepared.

First, a polyethylenenaphthalate film 21 having ITO film 22 with athickness of 1000 Å vapor deposited thereon was placed on a supportingstand and, after reduced to a pressure of 10⁻⁶ Torr, active species SiF₂^(*) formed similarly as in Example 24 were introduced into the filmforming chamber 101. Also, Si₃ H₆ gas, GeH₄ gas and PH₃ gas (diluted to1000 ppm with hydrogen gas) were respectively introduced into theactivation chamber (B) 123 to be activated. Then, the activated gaseswere introduced through the inflow pipe 124 into the film formingchamber 101. While maintaining the pressure in the film forming chamberat 0.1 Torr and the substrate temperature at 200° C., plasma was allowedto act from the discharging device 117 to form a n-type A-SiGe(H,X) film24 (film thickness 700 Å) doped with P.

Next, according to the same method as in formation of the n-typeA-SiGe(H,X) film except for introduction of B₂ H₆ gas (diluted to 300ppm with hydrogen gas) in place of PH₃ gas, an i-type A-SiGe(H,X) film25 (film thickness: 5000 Å) was formed.

Subsequently, by using B₂ H₆ gas (diluted to 1000 ppm with hydrogen gas)in place of PH₃ gas, following otherwise the same conditions as in thecase of n-type, an A-SiGe(H,X) film 26 (film thickness: 700 Å) dopedwith B was formed. Further, on this p-type film was formed by vapordeposition an aluminum electrode 27 with a thickness of 1000 Å toprovide a PIN type diode.

The diode element thus obtained (area 1 cm²) was subjected tomeasurement of I-V characteristic, and rectifying characteristic andphotovoltaic effect were evaluated. The results are shown in Table 3D.

Also, in photoirradiation characteristics, light was introduced from thesubstrate side, and a conversion efficiency of 7.3% or higher, an opencircuit voltage of 0.81 V and a short circuit current of 8.8 mA/cm² wereobtained at a photoirradiation intensity AMI (about 100 mW/cm²).

Examples 30-32

Except for using straight chain Ge₄ H₁₀, branched Ge₄ H₁₀ or H₆ Ge₆ F₆in place of GeH₄ as the germanium-containing compound, the same PIN typediode as in Example 29 was prepared in the same manner as in Example 29.The rectifying characteristic and photovoltaic effect were evaluated andthe results are shown in Table 3D.

From Table 3D, it can be seen that an A-SiGe(H,X) PIN type diode havingbetter optical and electrical characteristics as compared with the priorart can be obtained according to the present invention.

Example 33

By means of the device as shown in FIG. 3, i-type, p-type and n-typeoxygen-containing amorphous deposited films were formed according to theoperations as described below.

In FIG. 3, 101 is a film forming chamber, and a desired substrate 103 isplaced on a substrate supporting stand 102 provided internally therein.

104 is a heater for heating the substrate, and electricity is suppliedthrough a conductive wire 105 to generate heat.

The substrate temperature is not particularly limited, but it shouldpreferably be 30° to 450° C., more preferably 50° to 350° C., when thesubstrate is required to be heated in practicing the process of thepresent invention.

106 through 109 are gas feeding systems, and they are providedcorresponding to oxygen-containing compounds, and the kinds of gasesoptionally employed such as hydrogen, halogen compounds, inert gases,silicon-containing compounds, carbon-containing compounds,germanium-containing compounds, and compounds containing impurityelements as the component. When these gases employed are liquid underthe standard condition, a suitable gasifying device is provided.

In the drawing, symbols of the gas feeding sources 106 through 109affixed with a are branched pipes, those affixed with b flowmeters,those affixed with c pressure gauges for measuring the pressures on thehigher pressure side of the respective flowmeters, those affixed with dor e valves for controlling the flow rates of respective gases. 123 isthe activation chamber (B) for forming active species (B) and, aroundthe activation chamber 123, there is provided the microwave plasmagenerating device 122 for generating activation energy for formation ofactive species (B). The starting gas for formation of active species (B)supplied from the gas inflow pipe 110 is activated in the activationchamber (B), and the active species (B) formed is introduced through theinflow pipe 124 into the film forming chamber 101. 111 is a gas pressuregauge.

In the drawing, 112 shows an activation chamber (A), 113 an electricfurnace, 114 solid Si particles and 115 a pipe for introduction of agaseous compound containing silicon and halogen as the starting materialfor active species (A). The active species (A) formed in the activationchamber 112 is introduced through the inflow pipe 116 into the filmforming chamber 101.

117 is a discharging energy generating device and is provided with amatching box 117a, a cathode electrode 117b for introduction of highfrequency, etc.

The discharging energy from the discharging energy generating device 117is allowed to act on the active species flowing in the direction of thearrowhead 119, thereby causing active species to undergo mutuallychemical reaction and form an oxygen-containing amorphous depositionfilm on the whole or the desired portion of the substrate 103.

In the drawing, 120 shows a gas discharging valve and 121 a gasdischarging pipe.

First, a polyethyleneterephthalate film 103 was placed on a supportingstand 102, and the film forming chamber 101 was evacuated by use of anevacuating device to about 10⁻⁶ Torr. At the substrate temperatureindicated in Table 1E, from the gas feeding source 106, O₂ (diluted to10 vol. % gas or B₂ H₆ gas (each diluted to 1000 ppm with hydrogen gas)at 40 SCCM was introduced into the activation chamber (B) 123 throughthe gas inflow pipe 110. O₂ gas, etc. introduced into the activationchamber (B) 123 was activated by means of the microwave plasmagenerating device 122 to be converted to activated oxygen, etc., whichwas then introduced through the inflow pipe 124 into the film formingchamber 101.

On the other hand, the activation chamber (A) 122 was packed with solidSi particles 114, heated by the electric furnace 113 to be maintained atabout 1100° C., thereby bringing Si into red hot state, whereinto SiF₄was blown through the inflow pipe 115 from the bomb not shown, thusforming active species of SiF₂ ^(*), which were then introduced into thefilm forming chamber 101 via the inflow pipe 116.

While maintaining the inner pressure in the film forming chamber 101 at0.4 Torr, plasma was allowed to act from the discharging device 117 toform a non-doped or doped oxygen-containing amorphous deposited film(film thickness 700 Å). The film forming speed was 14 Å/sec.

Subsequently, each of the obtained samples was placed in a vacuumdeposition tank, wherein comb-type Al-gap electrode (gap length 250μ,width 5 mm) was formed under vacuum of 10⁻⁵ Torr, and the darkelectroconductivitity σ_(d) was determined by measuring dark current atan applied voltage of 10 V for evaluation of the film characteristics ofthe respective samples. The results are shown in Table 1E.

Examples 34-36

Except for using O₂ (diluted to 10 vol. % with He) and each of Si₂ H₆,Ge₂ H₆ and C₂ H₆, introducing these into the activation chamber (B) toform active species (B), which were then introduced into the filmforming chamber 101, oxygen-containing amorphous deposited films wereformed according to the same method and procedures as in Example 33. Thedark electroconductivities were measured for respective samples toobtain the results shown in Table 1E.

From Table 1E, it can be seen that oxygen-containing amorphous depositedfilms excellent in electrical characteristics and subjected tosatisfactory doping can be obtained according to the present invention.

Examples 37-40

Except for using H₃ OSiOSiH₃, H₃ GeOGeH₃, CO₂ or OF₂ in place of O₂,oxygen-containing amorphous deposited films were formed in the samemanner as in Example 33.

The thus obtained oxygen-containing amorphous deposited films were foundto be excellent in electrical characteristics and also dopedsatisfactorily.

Example 41

By means of the device as shown in FIG. 4, drum-shaped image formingmember for electrophotography with a layer constitution as shown in FIG.was prepared according to the operations as described below.

In FIG. 4, 201 shows a film forming chamber, 202 an activation chamber(A), 203 an electric furnace, 204 solid Si particles, 205 an inflow pipefor the starting material of active species (A), 206 a pipe forintroducing active species, 207 a motor, 208 a heater which is usedsimilarly as 104 in FIG. 3, 209 and 210 are blowing pipes, 211 analuminum cylinder substrate and 212 a gas discharging valve. 213 through216 are starting gas feeding sources similarly as 106 through 109 inFIG. 1, and 217-1 is a gas introducing pipe.

In the film forming chamber 201, the aluminum cylinder 211 is suspended,equipped internally thereof with the heater 208 so as to be rotatablewith the motor 207. 218 is a discharging generating device, and isprovided with a matching box 218a, a cathode electrode 218b forintroduction of high frequency, etc.

Also, the activation chamber (A) 202 is packed with solid Si particles204, heated by the electric furnace 203 to be maintained at about 1100°C. to bring Si into red hot state, whereinto SiF₄ is blown to formactive species of SiF₂ ^(*), which are then introduced into the filmforming chamber 201 via the inflow pipe 206.

On the other hand, through the inflow pipe 217-1, SiF₄, O₂ and H₂ wereintroduced into the activation chamber (B) 219. The SiF₄, O₂ and H₂gases introduced were subjected to activation treatment such as plasmaformation by means of the microwave plasma generating device 220 in theactivation chamber (B) 219 to become fluorinated silicon active species,oxygen active species activated oxygen and activated hydrogen, whichwere then introduced through the inflow pipe 217-2 into the film formingchamber 201. During this operation, if desired, inpurity gases such asPH₃, B₂ H₆, etc. were also activated by introduction into the activationchamber (B) 219. While maintaining the pressure in the film formingchamber 201 at 1.0 Torr, plasma was allowed to act from the dischargingdevice 218.

The aluminum cylinder 211 was heated to 200° C. by the heater 208,maintained thereat and rotated, while the discharging gas was dischargedby controlling adequately the opening of the discharging valve 212.Thus, photosensitive layer 13 was formed to a film thickness of 2000 Å.

Also, the intermediate layer 12 was formed prior to formation of thephotosensitive layer 13 to a film thickness of 2000 Å by introducing agas mixture of SiF₄, O₂ (SiF₄ : O₂ =1:10⁻⁵, He and B₂ H₆ (0.2% of B₂ H₆in terms of vol. %) through the inflow pipe 217-1.

Comparative example 5

According to the plasma CVD method of prior art, an image forming memberfor electrophotography having a layer constitution as shown in FIG. 1was formed by use of respective gases of SiF₄, O₂, He and B₂ H₆ by meansof the device having the same film forming chamber as the film formingchamber 201 provided with a high frequency means of 13.56 MHz.

The conditions for preparation of the drum-shaped image forming membersfor electrophotography obtained in Example 41 and Comparative example 5and their performances are shown in Table 2E.

Example 42

By means of the device as shown in FIG. 3, with the use of O₂ as theoxygen compound, a PIN type diode as shown in FIG. 2 was prepared.

First, a polyethylenenaphthalate film 21 having ITO film 22 with athickness of 1000 Å vapor deposited thereon was placed on a supportingstand and, after reduced to a pressure of 10⁻⁶ Torr, active species SiF₂^(*) formed similarly as in Example 33 were introduced into the filmforming chamber 101. Also, Si₃ H₆ gas and PH₃ gas (diluted to 1000 ppmwith hydrogen gas) were respectively introduced into the activationchamber (B) 123 to be activated. Then, the activated gases wereintroduced through the inflow pipe 116 into the film forming chamber101. While maintaining the pressure in the film forming chamber at 0.1Torr and the substrate temperature at 210° C., plasma was allowed to actfrom the discharging device 117 to form a n-type A-Si(H,X) film 24 (filmthickness 700 Å) doped with P.

Next, according to the same method as in formation of the n-typeA-Si(H,X) film except for stopping introduction of PH₃ gas, a non-dopedA-Si(H,X) film 25 (film thickness: 5000 Å) was formed.

Subsequently, by using O₂ gas and B₂ H₆ gas (diluted to 1000 ppm withhydrogen gas) together with Si₃ H₆ gas, following otherwise the sameconditions as in the case of n-type, a p-type oxygen containingA-Si(H,X) film 26 (film thickness: 700 Å) doped with B was formed.Further, on this p-type film was formed by vapor deposition an aluminumelectrode 27 with a thickness of 1000 Å to provide a PIN type diode.

The diode element thus obtained (area 1 cm²) was subjected tomeasurement of I-V characteristic, and rectifying characteristic andphotovoltaic effect were evaluated. The results are shown in Table 3E.

Also, in photoirradiation characteristics, light was introduced from thesubstrate side, and a conversion efficiency of 8.5 % or higher, an opencircuit voltage of 0.9 V and a short circuit current of 11.0 mA/cm² wereobtained at a photoirradiation intensity AMI (about 100 mW/cm²).

Examples 43-45

Except for using H₃ SiOSiH₃, H₃ GeOGeH₃, CO₂ or OF₂ in place of O₂ asthe oxygen compound, PIN type diodes similar to that prepared in Example42 were prepared in the same manner as in Example 42. The rectifyingcharacteristic and photovoltaic effect were evaluated and the resultsare shown in Table 3E.

From Table 3E, it can be seen that A-SiO(H,X) PIN type diode havingbetter optical and electrical characteristics as compared with the priorart can be obtained according to the present invention.

Example 46

By means of the device as shown in FIG. 3, i-type, p-type and n-typenitrogen-containing amorphous deposited films were formed according tothe operations as described below.

In FIG. 3, 101 is a film forming chamber, and a desired substrate 103 isplaced on a substrate supporting stand 102 provided internally therein.

104 is a heater for heating the substrate, and electricity is suppliedthrough a conductive wire 105 to generate heat. The heated substratetemperature is not particularly limited, but it should preferably be 30°to 450° C., more preferably 50° to 350° C., when the substrate isrequired to be heated in practicing the process of the presentinvention.

106 through 109 are gas feeding systems, and they are providedcorresponding to the nitrogen compounds, and the kinds of gasesoptionally employed such as hydrogen, halogen compounds, inert gases,silicon-containing compounds, carbon-containing compounds,germanium-containing compounds, oxygen-containing compounds andcompounds containing impurity elements as the component. When thesegases employed are liquid under the standard condition, a suitablegasifying device is provided. In the drawing, symbols of the gas feedingsources 106 through 109 affixed with a are branched pipes, those affixedwith b flowmeters, those affixed with c pressure gauges for measuringthe pressures on the higher pressure side of the respective flowmeters,those affixed with d or e valves for controlling the flow rates ofrespective gases. 123 is the activation chamber (B) for forming activespecies (B) and, around the activation chamber 123, there is providedthe microwave plasma generating device 122 for generating activationenergy for formation of active species (B). The starting gas forformation of active species (B) supplied from the gas inflow pipe 110 isactivated in the activation chamber (B), and the active species (B)formed is introduced through the inflow pipe 124 into the film formingchamber 101. 111 is a gas pressure gauge. In the drawing, 112 shows anactivation chamber (A), 113 an electric furnace, 114 solid Si particlesand 115 a pipe for introduction of a gaseous compound containing carbonand halogen as the starting material for active species (A). The activespecies (A) formed in the activation chamber 112 is introduced throughthe inflow pipe 116 into the film forming chamber 101.

117 is a discharging energy generating device and is provided with amatching box 117a, a cathode electrode 117b for introduction of highfrequency, etc.

The discharging energy from the discharging energy device 117 ispermitted to act on the active species flowing in the direction of thearrowhead 119, thereby causing the active species to undergo mutuallychemical reaction and form a nitrogen-containing deposited film on thewhole or the desired portion of the substrate 103. In the drawing, 120shows a gas discharging valve and 121 a gas discharging pipe.

First, a polyethyleneterephthalate film 103 was placed on a supportingstand 102, and the film forming chamber 101 was evacuated by use of anevacuating device to about 10⁻⁶ Torr. N₂ at 150 SCCM from the bomb forgas feeding 106 or a gas mixture thereof with PH₃ gas or B₂ H₆ gas (eachdiluted to 1000 ppm with hydrogen gas) at 40 SCCM was introduced intothe activation chamber (B) 123 through the gas inflow pipe 110. N₂ gas,etc. introduced into the activation chamber (B) 123 was activated bymeans of the microwave plasma generating device 122 to be converted toactivated nitrogen, etc. which was then introduced through the inflowpipe 124 into the film forming chamber 101.

On the other hand, the activation chamber (A) 22 was packed with solidSi particles 114, heated by the electric furnace 113 to be maintained atabout 1100° C., thereby bringing Si into red hot state, whereinto SiF₄was blown through the inflow pipe 115 from the bomb not shown, thusforming active species of SiF₂ ^(*), which were then introduced into thefilm forming chamber 101 via the inflow pipe 116.

Thus, while maintaining the inner pressure in the film forming chamber101 at 0.6 Torr, plasma was allowed to act from the discharging device117 to form a non-doped or doped nitrogen-containing amorphous depositedfilm (film thickness 700 Å). The film forming speed was 51 Å/sec.

Subsequently, each of the non-doped or p-type samples obtained wasplaced in a vacuum deposition tank, wherein a comb-type Al-gap electrode(gap length 250μ, width 5 mm) was formed under vacuum of 10⁻⁵ Torr, andthe dark electroconductivity σ_(d) was determined by measuring darkcurrent at an applied voltage of 12 V for evaluation of the filmcharacteristics of the respective samples. The results are shown inTable 1F.

Examples 47-49

Except for using Si₂ H₆, Ge₂ H₆ or C₂ H₆ together with N₂,nitrogen-containing amorphous deposited films were formed according tothe same method and procedures as in Example 46. The darkelectroconductivities were measured for respective samples to obtain theresults shown in Table 1F.

From Table 1F, it can be seen that nitrogen-containing amorphousdeposited films excellent in electrical characteristics can be obtainedaccording to the present invention, and also nitrogen-containingamorphous deposited films satisfactorily doped can be obtained.

Examples 50-53

Except for using NH₃, NOF, NO₂ or N₂ O in place of N₂,nitrogen-containing amorphous deposited films were formed in the samemanner as in Example 46.

The thus obtained nitrogen-containing amorphous deposited films werefound to be excellent in electrical characteristics and dopedsatisfactorily.

Example 54

By means of the device as shown in FIG. 4, a drum-shaped image formingmember for electrophotography with a layer constitution as shown in FIG.1 was prepared according to the operations as described below.

In FIG. 4, 201 shows a film forming chamber, 202 an activation chamber(A), 203 an electric furnace, 204 solid Si particles, 205 an inflow pipefor the starting material of active species (A), 206 a pipe forintroducing active species, 207 a motor, 208 a heater which is usedsimilarly as 104 in FIG. 3, 209 and 210 are blowing pipes, 211 analuminum cylinder substrate and 212 a gas discharging valve. 213 through216 are starting gas feeding sources similarly as 106 through 109 inFIG. 1, and 217-1 is a gas introducing pipe.

In the film forming chamber 201, the aluminum cylinder 211 is suspended,equipped internally thereof with the heater 208 so as to be rotatablewith the motor 207. 218 is a discharging generating device, and isprovided with a matching box 218a, a cathode electrode 218b forintroduction of high frequency, etc.

Also, the activation chamber (A) 202 is packed with solid Si particles204, heated by the electric furnace 203 to be maintained at about 1100°C. to bring Si into red hot state, whereinto SiF₄ is blown to formactive species of SiF₂ ^(*), which are then introduced into the filmforming chamber 201 via the inflow pipe 206.

On the other hand, through the inflow pipe 217-1, respective gases ofSi₂ H₆ and H₂ were introduced into the activation chamber (B) 219. TheSi₂ H₆ and H gases introduced were subjected to activation treatmentsuch as plasma formation by means of the microwave plasma generatingdevice 220 in the activation chamber (B) 219 to become hydrogenatedsilicon active species and activated hydrogen, which were thenintroduced through the inflow pipe 217-2 into the film forming chamber201. During this operation, if desired, impurity gases such as PH₃, B₂H₆, etc. were also introduced into the activation chamber (B) 219 to beactivated.

Then, while maintaining the pressure in the film forming chamber 201 at1.0 Torr, plasma was allowed to act from the discharging device 218.

The aluminum cylinder 211 was heated by the heater 208 to 280° C.,maintained thereat and rotated, while the discharging gas was dischargedby controlling adequately the opening of the discharging valve 212.Thus, photosensitive layer 13 was formed.

The intermediate layer 12 was formed prior to formation of thephotosensitive layer 13 to a film thickness of 2000 Å by introducing agas mixture of Si₂ H₆, N₂, H₂ and B₂ H₆ (0.2% of B₂ H₆ in terms of vol%) in addition to the gases employed during formation of thephotosensitive layer 13 through the inflow pipe 217-1.

Comparative example 6

According to the plasma CVD method in general, an image forming memberfor electrophotography having a layer constitution as shown in FIG. 1Cwas formed by use of respective gases of SiF₄, Si₂ H₆, N₂, H₂ and B₂ H₆by means of the device having the same film forming chamber as the filmforming chamber 201 provided with a high frequency means of 13.56 MHz.

The conditions for preparation of the drum-shaped image forming membersfor electrophotography obtained in Example 54 and Comparative example 6and their performances are shown in Table 2F.

Example 55

By means of the device as shown in FIG. 3, with use of N₂ as thenitrogen compound, a PIN type diode as shown in FIG. 2 was prepared.

First, a polyethylenenaphthalate film 21 having ITO film 22 with athickness of 1000 Å vapor deposited thereon was placed on a supportingstand and, after reduced to a pressure of 10⁻⁶ Torr, active species SiF₂^(*) formed similarly as in Example 46 were introduced into the filmforming chamber 101. Also, Si₃ H₆ gas and PH₃ gas (diluted to 1000 ppmwith hydrogen gas) were respectively introduced into the activationchamber (B) 123 to be activated. Then, the activated gases wereintroduced through the inflow pipe 116 into the film forming chamber101. While maintaining the pressure in the film forming chamber at 0.4Torr, plasma was allowed to act to form a n-type A-Si(H,X) film 24 (filmthickness 700 Å) doped with P.

Next, according to the same method as in formation of the n-typeA-Si(H,X) film except for stopping introduction of PH₃ gas, a non-dopedA-Si(H,X) film 25 (film thickness: 5000 Å) was formed.

Subsequently, by using N₂ gas and B₂ H₆ gas (diluted to 1000 ppm withhydrogen gas) together with Si₃ H₆ gas, following otherwise the sameconditions as in the case of n-type, a p-type A-SiN(H,X) film 26 (filmthickness: 700 Å) doped with B was formed. Further, on this p-type filmwas formed by vapor deposition an aluminum electrode 27 with a thicknessof 1000 Å to provide a PIN type diode.

The diode element thus obtained (area 1 cm²) was subjected tomeasurement of I-V characteristic, and rectifying characteristic andphotovoltaic effect were evaluated. The results are shown in Table 3F.

Also, in photoirradiation characteristics, light was introduced from thesubstrate side, and a conversion efficiency of 8.4% or higher, an opencircuit voltage of 0.9 V and a short circuit current of 10.2 mA/cm² wereobtained at a photoirradiation intensity AMI (about 100 mW/cm²).

Example 56

Except for using NO, N₂ O or N₂ O₄ in place of N₂ as the nitrogencompound, PIN type diodes similar to that preparation in Example 55 wereprepared in the same manner as in Example 55. The rectifyingcharacteristic and photovoltaic effect were evaluated and the resultsare shown in Table 3F.

From Table 3F, it can be seen that PIN type diode by use of A-SiN(H,X)having good optical and electrical characteristics can be obtainedaccording to the present invention.

                  TABLE 1A                                                        ______________________________________                                                      Example 1                                                                              Example 2                                              ______________________________________                                        Gas for forming active                                                                        H.sub.2    H.sub.2 /F.sub.2                                   species (B)                                                                   Substrate temperature                                                                         200        200                                                (°C.)                                                                  σd (Non-doped)                                                                          4.4 × 10.sup.-10                                                                   5.6 × 10.sup.-10                             (Ω · cm).sup.-1                                                σd (B-doped)                                                                            5.8 × 10.sup.-8                                                                    3.8 × 10.sup.-8                              (Ω · cm).sup.-1                                                σd (P-doped)                                                                            4.1 × 10.sup.-7                                                                    1.5 × 10.sup.-7                              (Ω · cm).sup.-1                                                ______________________________________                                    

                  TABLE 2A                                                        ______________________________________                                                                Comparative                                                         Example 3 example 1                                             ______________________________________                                        Gas for forming SiF.sub.4                                                     active species (A)                                                            Activation temperature                                                                        1100° C.                                               Main active species                                                                           SiF.sub.2 *                                                   Gas for forming H.sub.2                                                       active species (B)                                                            Inflow amount from                                                                            200 SCCM                                                      activation chamber (A)                                                        Inflow amount from                                                                            100 SCCM                                                      activation chamber (B)                                                        Inflow amount from          SiF.sub.4                                                                            200 SCCM                                   gas bomb                    H.sub.2                                                                              100 SCCM                                   Inner pressure in film                                                                        0.8 Torr    1.0 Torr                                          forming chamber                                                               Substrate temperature       280° C.                                    Film forming rate                                                                             35 Å/sec                                                                              5 Å/sec                                       RF discharging power                                                                          0.2 W/cm.sup.2                                                                            1.8 W/cm.sup.2                                    Layer thickness of                                                                            25μ      25μ                                            photosensitive layer 13                                                       Average number of image                                                                       2           15                                                defects in 10 drum-shaped                                                     image forming members                                                         for electrophotography                                                        Acceptance potential                                                                          ±5 V     ±30 V                                          irregularity in                                                               circumferential direction                                                     Acceptance potential                                                                          ±10 V    ±35 V                                          irregularity in                                                               axial direction                                                               Remarks         Example     Example                                                           according to                                                                              according to                                                      the process of                                                                            plasma CVD                                                        this invention                                                                            of prior art                                      ______________________________________                                    

                  TABLE 3A                                                        ______________________________________                                                       Example 4                                                                             Example 5                                              ______________________________________                                        Gas for film formation                                                                         H.sub.2   H.sub.2 /F.sub.2                                   Substrate temperature                                                                          220       220                                                (°C.)                                                                  Rectifying ratio of                                                                            7 × 10.sup.2                                                                      6 × 10.sup.2                                 diode (*1)                                                                    n value of diode (*2)                                                                          1.2       1.4                                                ______________________________________                                         (*1) Ratio of forward current to reverse current at voltage 1 V               (*2) n value (Quality Factor) in the current formula of pn junction: J =      Js {exp (eV/nRT) - 1}-                                                   

                                      TABLE 1B                                    __________________________________________________________________________               Example 6                                                                            Example 7                                                                            Example 8                                                                            Example 9                                     __________________________________________________________________________    Gas for forming                                                                          Si.sub.5 H.sub.10                                                                    Si.sub.4 H.sub.10                                                                    SiH.sub.3 SiH--                                                                      H.sub.6 Si.sub.6 F.sub.6                      active species (B)       (SiH.sub.3)SiH.sub.3                                 Substrate temperature                                                                    220    220    220    220                                           (°C.)                                                                  σd (Non-doped)                                                                     7.8 × 10.sup.-10                                                               4.3 × 10.sup.-10                                                               5.1 × 10.sup.-10                                                               2.7 × 10.sup.-10                        (Ω · cm).sup.-1                                                σd (B-doped)                                                                       6.9 × 10.sup.-9                                                                3.1 × 10.sup.-9                                                                4.5 × 10.sup.-9                                                                3.5 × 10.sup.-9                         (Ω · cm).sup.-1                                                σd (P-doped)                                                                       5.3 × 10.sup.-9                                                                3.3 × 10.sup.-9                                                                4.2 × 10.sup.-9                                                                3.2 × 10.sup.-9                         (Ω · cm).sup.-1                                                __________________________________________________________________________

                  TABLE 2B                                                        ______________________________________                                                               Comparative                                                          Example 10                                                                             example 2                                              ______________________________________                                        Gas for forming SiF.sub.4                                                     active species (A)                                                            Activation temperature                                                                        1100° C.                                               Main active species                                                                           SiF.sub.2 *                                                   Gas for forming Si.sub.2 H.sub.6 /H.sub.2                                     active species (B)                                                            Inflow amount from                                                                            200 SCCM                                                      activation chamber (A)                                                        Inflow amount from                                                                            100 SCCM                                                      activation chamber (B)                                                        Inflow amount from         SiF.sub.4                                                                             200 SCCM                                   gas bomb                   Si.sub.2 H.sub.6                                                                      100 SCCM                                                              H.sub.2 100 SCCM                                   Inner pressure in film                                                                        1.0 Torr   1.0 Torr                                           forming chamber                                                               Substrate temperature      280° C.                                     Film forming rate                                                                             38 Å/sec                                                                             7 Å/sec                                        RF discharging power                                                                          0.3 W/cm.sup.2                                                                           1.6 W/cm.sup.2                                     Layer thickness of                                                                            23μ     23μ                                             photosensitive layer 13                                                       Average number of image                                                                       4          15                                                 defects in 10 drum-shaped                                                     image forming members                                                         for electrophotography                                                        Acceptance potential                                                                          ±9 V    ±30 V                                           irregularity in                                                               circumferential direction                                                     Acceptance potential                                                                          ±16 V   ±35 V                                           irregularity in                                                               axial direction                                                               Remarks         Example    Example                                                            according to                                                                             according to                                                       the process of                                                                           plasma CVD                                                         this invention                                                                           of prior art                                       ______________________________________                                    

                                      TABLE 3B                                    __________________________________________________________________________               Example 11                                                                           Example 12                                                                           Example 13                                                                           Example 14                                    __________________________________________________________________________    Gas for forming                                                                          Si.sub.3 H.sub.6                                                                     Si.sub.4 H.sub.10                                                                    SiH.sub.3 SiH--                                                                      H.sub.6 Si.sub.6 F.sub.6                      active species (B)       (SiH.sub.3)SiH.sub.3                                 Substrate temperature                                                                    220    220    220    220                                           (°C.)                                                                  Rectifying ratio of                                                                      6.2 × 10.sup.2                                                                 4.1 × 10.sup.2                                                                 6.9 × 10.sup.2                                                                 2.5 × 10.sup.2                          diode (*1)                                                                    n value of diode (*2)                                                                    1.2    1.4    1.4    1.3                                           __________________________________________________________________________     (*1) Ratio of forward current to reverse current at voltage 1 V               (*2) n value (Quality Factor) in the current formula of pn junction: J =      Js {exp (eV/nRT) - 1}-                                                   

                                      TABLE 1C                                    __________________________________________________________________________               Example 15                                                                           Example 16                                                                           Example 17                                                                           Example 18                                    __________________________________________________________________________    Gas for forming                                                                          CH.sub.4                                                                             C.sub.2 H.sub.6                                                                      C.sub.2 H.sub.4                                                                      C.sub.2 H.sub.2                               active species (B)                                                            Substrate temperature                                                                    220    220    220    220                                           (°C.)                                                                  σd (Non-doped)                                                                     7.8 × 10.sup.-12                                                               4.1 × 10.sup.-12                                                               5.0 × 10.sup.-12                                                               3.1 × 10.sup.-12                        (Ω · cm).sup.-1                                                σd (B-doped)                                                                       6.9 × 10.sup.-9                                                                3.2 × 10.sup.-9                                                                4.2 × 10.sup.-9                                                                3.8 × 10.sup.-9                         (Ω · cm).sup.-1                                                σd (P-doped)                                                                       4.1 × 10.sup.-8                                                                7.9 × 10.sup.-8                                                                8.8 × 10.sup.-8                                                                5.1 × 10.sup.-8                         (Ω · cm).sup.-1                                                __________________________________________________________________________

                  TABLE 2C                                                        ______________________________________                                                               Comparative                                                         Example 19                                                                              example 3                                              ______________________________________                                        Gas for forming                                                                              SiF.sub.4                                                      active species (A)                                                            Activation temperature                                                                       1100° C.                                                Main active species                                                                          SiF.sub.2 *                                                    Gas for forming                                                                              CH.sub.4 /Si.sub.2 H.sub.6 /H.sub.2                            active species (B)                                                                           (Volume ratio                                                                 0.5:1:1)                                                       Inflow amount from                                                                           200 SCCM                                                       activation chamber (A)                                                        Inflow amount from                                                                           100 SCCM                                                       activation chamber (B)                                                        Inflow amount from         SiF.sub.4                                                                             200 SCCM                                   gas bomb                   CH.sub.4                                                                               50 SCCM                                                              Si.sub.2 H.sub.6                                                                      100 SCCM                                                              H.sub.2 100 SCCM                                   Inner pressure in film                                                                       1.0 Torr    1.0 Torr                                           forming chamber                                                               Substrate temperature      280° C.                                     Film forming rate                                                                            42 Å/sec                                                                              5 Å/sec                                        RF discharging power                                                                         0.3 w/cm.sup.2                                                                            1.8 w/cm.sup.2                                     Layer thickness of                                                                           22μ      22μ                                             photosensitive layer 13                                                       Average number of image                                                                      3           16                                                 defects in 10 drum-shaped                                                     image forming members                                                         for electrophotography                                                        Acceptance potential                                                                         ±11 V    ±28 V                                           irregularity in                                                               circumferential direction                                                     Acceptance potential                                                                         ±14 V    ±33 V                                           irregularity in                                                               axial direction                                                               Remarks        Example     Example                                                           according to                                                                              according to                                                      the process of                                                                            plasma CVD                                                        this invention                                                                            of prior art                                       ______________________________________                                    

                                      TABLE 3C                                    __________________________________________________________________________               Example 20                                                                           Example 21                                                                           Example 22                                                                           Example 23                                    __________________________________________________________________________    Gas for forming                                                                          CH.sub.4                                                                             C.sub.2 H.sub.6                                                                      C.sub.2 H.sub.4                                                                      C.sub.2 H.sub.2                               active species (B)                                                            Substrate temperature                                                                    220    220    220    220                                           (°C.)                                                                  Rectifying ratio of                                                                      7.9 × 10.sup.2                                                                 8.2 × 10.sup.2                                                                 6.6 × 10.sup.2                                                                 8.4 × 10.sup.2                          diode (*1)                                                                    n value of diode (*2)                                                                    1.2    1.4    1.4    1.3                                           __________________________________________________________________________     (*1) Ratio of forward current to reverse current at voltage 1 V               (*2) n value (Quality Factor) in the current formula of pn junction: J =      Js {exp (eV/nRT) - 1}-                                                   

                                      TABLE 1D                                    __________________________________________________________________________               Example 24                                                                           Example 25                                                                           Example 26                                                                           Example 27                                    __________________________________________________________________________    Gas for forming                                                                          GeH.sub.4                                                                            Straight                                                                             Branched                                                                             H.sub.6 Ge.sub.6 F.sub.6                      active species (B)                                                                              chain Ge.sub.4 H.sub.10                                                              Ge.sub.4 H.sub.10                                    Substrate temperature                                                                    210    200    205    205                                           (°C.)                                                                  σd (Non-doped)                                                                     3.4 × 10.sup.-10                                                               2.5 × 10.sup.-10                                                               3.1 × 10.sup.-10                                                               6.5 × 10.sup.-10                        (Ω · cm).sup.-1                                                σd (B-doped)                                                                       5.2 × 10.sup.-6                                                                3.4 × 10.sup.-6                                                                5.9 × 10.sup.-6                                                                7.3 × 10.sup.-6                         (Ω · cm).sup.-1                                                σd (P-doped)                                                                       3.6 × 10.sup.-5                                                                1.7 × 10.sup.-5                                                                5.3 × 10.sup.-5                                                                1.2 × 10.sup.-5                         (Ω · cm).sup.-1                                                __________________________________________________________________________

                  TABLE 2D                                                        ______________________________________                                                               Comparative                                                         Example 28                                                                              example 4                                              ______________________________________                                        Gas for forming                                                                              SiF.sub.4                                                      active species (A)                                                            Activation temperature                                                                       1100° C.                                                Main active species                                                                          SiF.sub.2 *                                                    Gas for forming                                                                              Si.sub.2 H.sub.6 /GeH.sub.4 /H.sub.2                           active species (B)                                                            Inflow amount from                                                                           200 SCCM                                                       activation chamber (A)                                                        Inflow amount from                                                                           100 SCCM                                                       activation chamber (B)                                                        Inflow amount from         SiF.sub.4                                                                             200 SCCM                                   gas bomb                   Si.sub.2 H.sub.6                                                                      100 SCCM                                                              GeH.sub.4                                                                              50 SCCM                                                              H.sub.2 100 SCCM                                   Inner pressure in film                                                                       1.0 Torr    1.0 Torr                                           forming chamber                                                               Substrate temperature      260° C.                                     Film forming rate                                                                            36 Å/sec                                                                              5 Å/sec                                        RF discharging power                                                                         0.5 W/cm.sup.2                                                                            1.8 W/cm.sup.2                                     Layer thickness of                                                                           21μ      21μ                                             photosensitive layer 13                                                       Average number of image                                                                      2           20                                                 defects in 10 drum-shaped                                                     image forming members                                                         for electrophotography                                                        Acceptance potential                                                                         ±8 V     ±35 V                                           irregularity in                                                               circumferential direction                                                     Acceptance potential                                                                         ±15 V    ±40 V                                           irregularity in                                                               axial direction                                                               Remarks        Example     Example                                                           according to                                                                              according to                                                      the process of                                                                            plasma CVD                                                        this invention                                                                            of prior art                                       ______________________________________                                    

                                      TABLE 3D                                    __________________________________________________________________________               Example 29                                                                           Example 30                                                                           Example 31                                                                           Example 32                                    __________________________________________________________________________    Gas for forming                                                                          GeH.sub.4                                                                            Straight                                                                             Branched                                                                             H.sub.6 Ge.sub.6 F.sub.6                      active species (B)                                                                              chain Ge.sub.4 H.sub.10                                                              Ge.sub.4 H.sub.10                                    Substrate temperature                                                                    200    200    200    210                                           (°C.)                                                                  Rectifying ratio of                                                                      5.8 × 10.sup.2                                                                 3.4 × 10.sup.2                                                                 6.8 × 10.sup.2                                                                 2.3 × 10.sup.2                          diode (*1)                                                                    n value of diode (*2)                                                                    1.26   1.3    1.32   1.34                                          __________________________________________________________________________     (*1) Ratio of forward current to reverse current at voltage 1 V               (*2) n value (Quality Factor) in the current formula of pn junction: J =      Js {exp (eV/nRT) - 1}-                                                   

                                      TABLE 1E                                    __________________________________________________________________________               Example 33                                                                           Example 34                                                                           Example 35                                                                            Example 36                                   __________________________________________________________________________    Gas for forming                                                                          O.sub.2 /He                                                                          O.sub.2 /He/Si.sub.2 H.sub.6                                                         O.sub.2 /He/Ge.sub.2 H.sub.6                                                          O.sub.2 /He/C.sub.2 H.sub.6                  active species (B)                                                            σd (Non-doped)                                                                     7.8 × 10.sup.-12                                                               4.6 × 10.sup.-10                                                               5.3 × 10.sup.-9                                                                 9.1 × 10.sup.-11                       (Ω · cm).sup.-1                                                σd (B-doped)                                                                       8.5 × 10.sup.-11                                                               9.2 × 10.sup.-9                                                                3.8 × 10.sup.-8                                                                 2.7 × 10.sup.-10                       (Ω · cm).sup.-1                                                σd (P-doped)                                                                       9.5 × 10.sup.-11                                                               3.3 × 10.sup.-9                                                                4.3 × 10.sup.-8                                                                 1.5 × 10.sup.-10                       (Ω · cm).sup.-1                                                __________________________________________________________________________

                  TABLE 2E                                                        ______________________________________                                                              Comparative                                                          Example 41                                                                             example 5                                               ______________________________________                                        Gas for forming                                                                              SiF.sub.4                                                      active species (A)                                                            Activation temperature                                                                       1100° C.                                                Main active species                                                                          SiF.sub.2 *                                                    Gas for forming                                                                              SiF.sub.4 /O.sub.2 He                                          active species (B)                                                            Inflow amount from (B)                                                                       200 SCCM                                                       Inflow amount from (C)                                                                       100 SCCM                                                       Inflow amount from        SiF.sub.4                                                                              200 SCCM                                   gas bomb                  O.sub.2 (Si.sub.2 H.sub.6 :O.sub.2                                            = 1:10.sup.-5                                                           He     100 SCCM                                           Inner pressure in film                                                                       1.0 Torr   1.0 Torr                                            forming chamber                                                               Substrate temperature     260° C.                                      Film forming rate                                                                            13 Å/sec                                                                             2 Å/sec                                         Plasma RF power                                                                              0.6 W/cm.sup.2                                                                           1.8 W/cm.sup.2                                      Layer thickness of                                                                           25μ     25μ                                              photosensitive layer 13                                                       Average number of image                                                                      3          15                                                  defects in 10 drum-shaped                                                     image forming members                                                         for electrophotography                                                        Acceptance potential                                                                         ±5 V    ±30 V                                            irregularity in                                                               circumferential direction                                                     Acceptance potential                                                                         ±15 V   ±35 V                                            irregularity in                                                               axial direction                                                               Remarks        Example    Example                                                            according to                                                                             according to                                                       the process of                                                                           plasma CVD                                                         this invention                                                                           of prior art                                        ______________________________________                                    

                                      TABLE 3E                                    __________________________________________________________________________               Example 42                                                                           Example 43                                                                           Example 44                                                                           Example 45                                    __________________________________________________________________________    Gas for forming                                                                          O.sub.2                                                                              H.sub.3 SiOSiH.sub.3                                                                 H.sub.3 GeOGeH.sub.3                                                                 OF.sub.2                                      active species (B)                                                            Rectifying ratio of                                                                      4.2 × 10.sup.2                                                                 6.6 × 10.sup.2                                                                 4.3 × 10.sup.2                                                                 3.7 × 10.sup.2                          diode (*1)                                                                    n value of diode (*2)                                                                    1.1    1.2    1.3    1.25                                          __________________________________________________________________________     (*1) Ratio of forward current to reverse current at voltage 1 V               (*2) n value (Quality Factor) in the current formula of pn junction: J =      Js {exp (eV/nRT) - 1}-                                                   

                                      TABLE 1F                                    __________________________________________________________________________               Example 46                                                                           Example 47                                                                           Example 48                                                                           Example 49                                    __________________________________________________________________________    Gas for forming                                                                          N.sub.2                                                                              N.sub.2 /Si.sub.2 H.sub.6                                                            N.sub.2 /Ge.sub.2 H.sub.6                                                            N.sub.2 /C.sub.2 H.sub.6                      active species (B)                                                            Substrate temperature                                                                    200    200    210    200                                           (°C.)                                                                  σd (Non-doped)                                                                     4.9 × 10.sup.-12                                                               7.3 × 10.sup.-10                                                               4.6 × 10.sup.-9                                                                5.9 × 10.sup.-11                        (Ω · cm).sup.-1                                                σd (B-doped)                                                                       9.1 × 10.sup.-11                                                               4.7 × 10.sup.-9                                                                3.4 × 10.sup.-8                                                                7.2 × 10.sup.-10                        (Ω · cm).sup.-1                                                σd (P-doped)                                                                       5.1 × 10.sup.-10                                                               4.0 × 10.sup.-8                                                                5.2 × 10.sup.-7                                                                6.4 × 10.sup.-9                         (Ω · cm).sup.-1                                                __________________________________________________________________________

                  TABLE 2F                                                        ______________________________________                                                               Comparative                                                          Example 54                                                                             example 6                                              ______________________________________                                        Gas for forming SiF.sub.4                                                     active species (A)                                                            Activation temperature                                                                        1100° C.                                               Main active species                                                                           SiF.sub.2 *                                                   Gas for forming Si.sub.2 H.sub.6 /N.sub.2 /H.sub.2                            active species (B)                                                            Inflow amount from                                                                            200 SCCM                                                      activation chamber (A)                                                        Inflow amount from                                                                            100 SCCM                                                      activation chamber (B)                                                        Inflow amount from         SiF.sub.4                                                                             200 SCCM                                   gas bomb                   Si.sub.2 H.sub.6                                                                      100 SCCM                                                              N.sub.2  50 SCCM                                                              H.sub.2 100 SCCM                                   Inner pressure in film                                                                        1.0 Torr   1.0 Torr                                           forming chamber                                                               Film forming rate                                                                             35 Å/sec                                                                             5 Å/sec                                        RF discharging power                                                                          0.2 W/cm.sup.2                                                                           1.8 W/cm.sup.2                                     Layer thickness of                                                                            25μ     25μ                                             photosensitive layer 13                                                       Average number of image                                                                       3          15                                                 defects in 10 drum-shaped                                                     image forming members                                                         for electrophotography                                                        Acceptance potential                                                                          ±8 V    ±30 V                                           irregularity in                                                               circumferential direction                                                     Acceptance potential                                                                          ±12 V   ±34 V                                           irregularity in                                                               axial direction                                                               Remarks         Example    Example                                                            according to                                                                             according to                                                       the process of                                                                           plasma CVD                                                         this invention                                                                           of prior art                                                                  Substrate tem-                                                                perature 280° C.                            ______________________________________                                    

                                      TABLE 3F                                    __________________________________________________________________________               Example 55                                                                           Example 56                                                                           Example 57                                                                           Example 58                                    __________________________________________________________________________    Gas for forming                                                                          N.sub.2                                                                              NO     N.sub.2 O                                                                            N.sub.2 O.sub.4                               active species (B)                                                            Substrate temperature                                                                    220    210    220    215                                           (°C.)                                                                  Rectifying ratio of                                                                      4.1 × 10.sup.2                                                                 4.2 × 10.sup.2                                                                 5.1 × 10.sup.2                                                                 7.2 × 10.sup.2                          diode (*1)                                                                    n value of diode (*2)                                                                    1.1    1.2    1.3    1.1                                           __________________________________________________________________________     (*1) Ratio of forward current to reverse current at voltage 1 V               (*2) n value (Quality Factor) in the current formula of pn junction: J =      Js {exp (eV/nRT) - 1}-                                                   

What is claimed is:
 1. A process for depositing a film on a substrate,comprising the steps of:separately preactivating (i) a compoundcontaining silicon and a halogen and (ii) a substance for film formationselected from the group consisting of H₂, F₂, Cl₂, Br₂ I₂ andgermanium-coating compounds, said compounds (i) and (ii) beingindividually preactivated by being decomposed to form respectivelymutually reactive species (A) and (B); separately introducing saidactive species (A) and (B) into a film-forming space containing thereina substrate wherein the proportion in amount of said active species (A)to said active species (B) is 10:1 to 1:10; mixing said active species(A) and (B) within said film-forming space; and applying dischargeenergy to the mixture of said active species (A) and (B) to chemicallyreact said active species (A) and (B) with each other to deposit saidfilm on said substrate wherein the life of said active species (A) is0.1 second or longer.
 2. A process according to claim 1, wherein saidactive species (A) is formed by decomposing a partially or whollyhalogen substituted chain or cyclic silane compound.